heap.cc revision 0c8c303c20cdaaf54d26e45cc17dc5afb820d8ef
1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "heap.h" 18 19#define ATRACE_TAG ATRACE_TAG_DALVIK 20#include <cutils/trace.h> 21 22#include <limits> 23#include <memory> 24#include <vector> 25 26#include "base/allocator.h" 27#include "base/dumpable.h" 28#include "base/histogram-inl.h" 29#include "base/stl_util.h" 30#include "common_throws.h" 31#include "cutils/sched_policy.h" 32#include "debugger.h" 33#include "dex_file-inl.h" 34#include "gc/accounting/atomic_stack.h" 35#include "gc/accounting/card_table-inl.h" 36#include "gc/accounting/heap_bitmap-inl.h" 37#include "gc/accounting/mod_union_table.h" 38#include "gc/accounting/mod_union_table-inl.h" 39#include "gc/accounting/remembered_set.h" 40#include "gc/accounting/space_bitmap-inl.h" 41#include "gc/collector/concurrent_copying.h" 42#include "gc/collector/mark_compact.h" 43#include "gc/collector/mark_sweep-inl.h" 44#include "gc/collector/partial_mark_sweep.h" 45#include "gc/collector/semi_space.h" 46#include "gc/collector/sticky_mark_sweep.h" 47#include "gc/reference_processor.h" 48#include "gc/space/bump_pointer_space.h" 49#include "gc/space/dlmalloc_space-inl.h" 50#include "gc/space/image_space.h" 51#include "gc/space/large_object_space.h" 52#include "gc/space/rosalloc_space-inl.h" 53#include "gc/space/space-inl.h" 54#include "gc/space/zygote_space.h" 55#include "gc/task_processor.h" 56#include "entrypoints/quick/quick_alloc_entrypoints.h" 57#include "heap-inl.h" 58#include "image.h" 59#include "intern_table.h" 60#include "mirror/art_field-inl.h" 61#include "mirror/class-inl.h" 62#include "mirror/object.h" 63#include "mirror/object-inl.h" 64#include "mirror/object_array-inl.h" 65#include "mirror/reference-inl.h" 66#include "os.h" 67#include "reflection.h" 68#include "runtime.h" 69#include "ScopedLocalRef.h" 70#include "scoped_thread_state_change.h" 71#include "handle_scope-inl.h" 72#include "thread_list.h" 73#include "well_known_classes.h" 74 75namespace art { 76 77namespace gc { 78 79static constexpr size_t kCollectorTransitionStressIterations = 0; 80static constexpr size_t kCollectorTransitionStressWait = 10 * 1000; // Microseconds 81// Minimum amount of remaining bytes before a concurrent GC is triggered. 82static constexpr size_t kMinConcurrentRemainingBytes = 128 * KB; 83static constexpr size_t kMaxConcurrentRemainingBytes = 512 * KB; 84// Sticky GC throughput adjustment, divided by 4. Increasing this causes sticky GC to occur more 85// relative to partial/full GC. This may be desirable since sticky GCs interfere less with mutator 86// threads (lower pauses, use less memory bandwidth). 87static constexpr double kStickyGcThroughputAdjustment = 1.0; 88// Whether or not we compact the zygote in PreZygoteFork. 89static constexpr bool kCompactZygote = kMovingCollector; 90// How many reserve entries are at the end of the allocation stack, these are only needed if the 91// allocation stack overflows. 92static constexpr size_t kAllocationStackReserveSize = 1024; 93// Default mark stack size in bytes. 94static const size_t kDefaultMarkStackSize = 64 * KB; 95// Define space name. 96static const char* kDlMallocSpaceName[2] = {"main dlmalloc space", "main dlmalloc space 1"}; 97static const char* kRosAllocSpaceName[2] = {"main rosalloc space", "main rosalloc space 1"}; 98static const char* kMemMapSpaceName[2] = {"main space", "main space 1"}; 99static const char* kNonMovingSpaceName = "non moving space"; 100static const char* kZygoteSpaceName = "zygote space"; 101static constexpr size_t kGSSBumpPointerSpaceCapacity = 32 * MB; 102static constexpr bool kGCALotMode = false; 103// GC alot mode uses a small allocation stack to stress test a lot of GC. 104static constexpr size_t kGcAlotAllocationStackSize = 4 * KB / 105 sizeof(mirror::HeapReference<mirror::Object>); 106// Verify objet has a small allocation stack size since searching the allocation stack is slow. 107static constexpr size_t kVerifyObjectAllocationStackSize = 16 * KB / 108 sizeof(mirror::HeapReference<mirror::Object>); 109static constexpr size_t kDefaultAllocationStackSize = 8 * MB / 110 sizeof(mirror::HeapReference<mirror::Object>); 111 112Heap::Heap(size_t initial_size, size_t growth_limit, size_t min_free, size_t max_free, 113 double target_utilization, double foreground_heap_growth_multiplier, 114 size_t capacity, size_t non_moving_space_capacity, const std::string& image_file_name, 115 const InstructionSet image_instruction_set, CollectorType foreground_collector_type, 116 CollectorType background_collector_type, 117 space::LargeObjectSpaceType large_object_space_type, size_t large_object_threshold, 118 size_t parallel_gc_threads, size_t conc_gc_threads, bool low_memory_mode, 119 size_t long_pause_log_threshold, size_t long_gc_log_threshold, 120 bool ignore_max_footprint, bool use_tlab, 121 bool verify_pre_gc_heap, bool verify_pre_sweeping_heap, bool verify_post_gc_heap, 122 bool verify_pre_gc_rosalloc, bool verify_pre_sweeping_rosalloc, 123 bool verify_post_gc_rosalloc, bool use_homogeneous_space_compaction_for_oom, 124 uint64_t min_interval_homogeneous_space_compaction_by_oom) 125 : non_moving_space_(nullptr), 126 rosalloc_space_(nullptr), 127 dlmalloc_space_(nullptr), 128 main_space_(nullptr), 129 collector_type_(kCollectorTypeNone), 130 foreground_collector_type_(foreground_collector_type), 131 background_collector_type_(background_collector_type), 132 desired_collector_type_(foreground_collector_type_), 133 pending_task_lock_(nullptr), 134 parallel_gc_threads_(parallel_gc_threads), 135 conc_gc_threads_(conc_gc_threads), 136 low_memory_mode_(low_memory_mode), 137 long_pause_log_threshold_(long_pause_log_threshold), 138 long_gc_log_threshold_(long_gc_log_threshold), 139 ignore_max_footprint_(ignore_max_footprint), 140 zygote_creation_lock_("zygote creation lock", kZygoteCreationLock), 141 zygote_space_(nullptr), 142 large_object_threshold_(large_object_threshold), 143 collector_type_running_(kCollectorTypeNone), 144 last_gc_type_(collector::kGcTypeNone), 145 next_gc_type_(collector::kGcTypePartial), 146 capacity_(capacity), 147 growth_limit_(growth_limit), 148 max_allowed_footprint_(initial_size), 149 native_footprint_gc_watermark_(initial_size), 150 native_need_to_run_finalization_(false), 151 // Initially assume we perceive jank in case the process state is never updated. 152 process_state_(kProcessStateJankPerceptible), 153 concurrent_start_bytes_(std::numeric_limits<size_t>::max()), 154 total_bytes_freed_ever_(0), 155 total_objects_freed_ever_(0), 156 num_bytes_allocated_(0), 157 native_bytes_allocated_(0), 158 verify_missing_card_marks_(false), 159 verify_system_weaks_(false), 160 verify_pre_gc_heap_(verify_pre_gc_heap), 161 verify_pre_sweeping_heap_(verify_pre_sweeping_heap), 162 verify_post_gc_heap_(verify_post_gc_heap), 163 verify_mod_union_table_(false), 164 verify_pre_gc_rosalloc_(verify_pre_gc_rosalloc), 165 verify_pre_sweeping_rosalloc_(verify_pre_sweeping_rosalloc), 166 verify_post_gc_rosalloc_(verify_post_gc_rosalloc), 167 /* For GC a lot mode, we limit the allocations stacks to be kGcAlotInterval allocations. This 168 * causes a lot of GC since we do a GC for alloc whenever the stack is full. When heap 169 * verification is enabled, we limit the size of allocation stacks to speed up their 170 * searching. 171 */ 172 max_allocation_stack_size_(kGCALotMode ? kGcAlotAllocationStackSize 173 : (kVerifyObjectSupport > kVerifyObjectModeFast) ? kVerifyObjectAllocationStackSize : 174 kDefaultAllocationStackSize), 175 current_allocator_(kAllocatorTypeDlMalloc), 176 current_non_moving_allocator_(kAllocatorTypeNonMoving), 177 bump_pointer_space_(nullptr), 178 temp_space_(nullptr), 179 min_free_(min_free), 180 max_free_(max_free), 181 target_utilization_(target_utilization), 182 foreground_heap_growth_multiplier_(foreground_heap_growth_multiplier), 183 total_wait_time_(0), 184 total_allocation_time_(0), 185 verify_object_mode_(kVerifyObjectModeDisabled), 186 disable_moving_gc_count_(0), 187 running_on_valgrind_(Runtime::Current()->RunningOnValgrind()), 188 use_tlab_(use_tlab), 189 main_space_backup_(nullptr), 190 min_interval_homogeneous_space_compaction_by_oom_( 191 min_interval_homogeneous_space_compaction_by_oom), 192 last_time_homogeneous_space_compaction_by_oom_(NanoTime()), 193 pending_collector_transition_(nullptr), 194 pending_heap_trim_(nullptr), 195 use_homogeneous_space_compaction_for_oom_(use_homogeneous_space_compaction_for_oom) { 196 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 197 LOG(INFO) << "Heap() entering"; 198 } 199 // If we aren't the zygote, switch to the default non zygote allocator. This may update the 200 // entrypoints. 201 const bool is_zygote = Runtime::Current()->IsZygote(); 202 if (!is_zygote) { 203 // Background compaction is currently not supported for command line runs. 204 if (background_collector_type_ != foreground_collector_type_) { 205 VLOG(heap) << "Disabling background compaction for non zygote"; 206 background_collector_type_ = foreground_collector_type_; 207 } 208 } 209 ChangeCollector(desired_collector_type_); 210 live_bitmap_.reset(new accounting::HeapBitmap(this)); 211 mark_bitmap_.reset(new accounting::HeapBitmap(this)); 212 // Requested begin for the alloc space, to follow the mapped image and oat files 213 uint8_t* requested_alloc_space_begin = nullptr; 214 if (!image_file_name.empty()) { 215 std::string error_msg; 216 space::ImageSpace* image_space = space::ImageSpace::Create(image_file_name.c_str(), 217 image_instruction_set, 218 &error_msg); 219 if (image_space != nullptr) { 220 AddSpace(image_space); 221 // Oat files referenced by image files immediately follow them in memory, ensure alloc space 222 // isn't going to get in the middle 223 uint8_t* oat_file_end_addr = image_space->GetImageHeader().GetOatFileEnd(); 224 CHECK_GT(oat_file_end_addr, image_space->End()); 225 requested_alloc_space_begin = AlignUp(oat_file_end_addr, kPageSize); 226 } else { 227 LOG(WARNING) << "Could not create image space with image file '" << image_file_name << "'. " 228 << "Attempting to fall back to imageless running. Error was: " << error_msg; 229 } 230 } 231 /* 232 requested_alloc_space_begin -> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 233 +- nonmoving space (non_moving_space_capacity)+- 234 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 235 +-????????????????????????????????????????????+- 236 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 237 +-main alloc space / bump space 1 (capacity_) +- 238 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 239 +-????????????????????????????????????????????+- 240 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 241 +-main alloc space2 / bump space 2 (capacity_)+- 242 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 243 */ 244 // We don't have hspace compaction enabled with GSS. 245 if (foreground_collector_type_ == kCollectorTypeGSS) { 246 use_homogeneous_space_compaction_for_oom_ = false; 247 } 248 bool support_homogeneous_space_compaction = 249 background_collector_type_ == gc::kCollectorTypeHomogeneousSpaceCompact || 250 use_homogeneous_space_compaction_for_oom_; 251 // We may use the same space the main space for the non moving space if we don't need to compact 252 // from the main space. 253 // This is not the case if we support homogeneous compaction or have a moving background 254 // collector type. 255 bool separate_non_moving_space = is_zygote || 256 support_homogeneous_space_compaction || IsMovingGc(foreground_collector_type_) || 257 IsMovingGc(background_collector_type_); 258 if (foreground_collector_type == kCollectorTypeGSS) { 259 separate_non_moving_space = false; 260 } 261 std::unique_ptr<MemMap> main_mem_map_1; 262 std::unique_ptr<MemMap> main_mem_map_2; 263 uint8_t* request_begin = requested_alloc_space_begin; 264 if (request_begin != nullptr && separate_non_moving_space) { 265 request_begin += non_moving_space_capacity; 266 } 267 std::string error_str; 268 std::unique_ptr<MemMap> non_moving_space_mem_map; 269 if (separate_non_moving_space) { 270 // If we are the zygote, the non moving space becomes the zygote space when we run 271 // PreZygoteFork the first time. In this case, call the map "zygote space" since we can't 272 // rename the mem map later. 273 const char* space_name = is_zygote ? kZygoteSpaceName: kNonMovingSpaceName; 274 // Reserve the non moving mem map before the other two since it needs to be at a specific 275 // address. 276 non_moving_space_mem_map.reset( 277 MemMap::MapAnonymous(space_name, requested_alloc_space_begin, 278 non_moving_space_capacity, PROT_READ | PROT_WRITE, true, &error_str)); 279 CHECK(non_moving_space_mem_map != nullptr) << error_str; 280 // Try to reserve virtual memory at a lower address if we have a separate non moving space. 281 request_begin = reinterpret_cast<uint8_t*>(300 * MB); 282 } 283 // Attempt to create 2 mem maps at or after the requested begin. 284 main_mem_map_1.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[0], request_begin, capacity_, 285 &error_str)); 286 CHECK(main_mem_map_1.get() != nullptr) << error_str; 287 if (support_homogeneous_space_compaction || 288 background_collector_type_ == kCollectorTypeSS || 289 foreground_collector_type_ == kCollectorTypeSS) { 290 main_mem_map_2.reset(MapAnonymousPreferredAddress(kMemMapSpaceName[1], main_mem_map_1->End(), 291 capacity_, &error_str)); 292 CHECK(main_mem_map_2.get() != nullptr) << error_str; 293 } 294 // Create the non moving space first so that bitmaps don't take up the address range. 295 if (separate_non_moving_space) { 296 // Non moving space is always dlmalloc since we currently don't have support for multiple 297 // active rosalloc spaces. 298 const size_t size = non_moving_space_mem_map->Size(); 299 non_moving_space_ = space::DlMallocSpace::CreateFromMemMap( 300 non_moving_space_mem_map.release(), "zygote / non moving space", kDefaultStartingSize, 301 initial_size, size, size, false); 302 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 303 CHECK(non_moving_space_ != nullptr) << "Failed creating non moving space " 304 << requested_alloc_space_begin; 305 AddSpace(non_moving_space_); 306 } 307 // Create other spaces based on whether or not we have a moving GC. 308 if (IsMovingGc(foreground_collector_type_) && foreground_collector_type_ != kCollectorTypeGSS) { 309 // Create bump pointer spaces. 310 // We only to create the bump pointer if the foreground collector is a compacting GC. 311 // TODO: Place bump-pointer spaces somewhere to minimize size of card table. 312 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 1", 313 main_mem_map_1.release()); 314 CHECK(bump_pointer_space_ != nullptr) << "Failed to create bump pointer space"; 315 AddSpace(bump_pointer_space_); 316 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 317 main_mem_map_2.release()); 318 CHECK(temp_space_ != nullptr) << "Failed to create bump pointer space"; 319 AddSpace(temp_space_); 320 CHECK(separate_non_moving_space); 321 } else { 322 CreateMainMallocSpace(main_mem_map_1.release(), initial_size, growth_limit_, capacity_); 323 CHECK(main_space_ != nullptr); 324 AddSpace(main_space_); 325 if (!separate_non_moving_space) { 326 non_moving_space_ = main_space_; 327 CHECK(!non_moving_space_->CanMoveObjects()); 328 } 329 if (foreground_collector_type_ == kCollectorTypeGSS) { 330 CHECK_EQ(foreground_collector_type_, background_collector_type_); 331 // Create bump pointer spaces instead of a backup space. 332 main_mem_map_2.release(); 333 bump_pointer_space_ = space::BumpPointerSpace::Create("Bump pointer space 1", 334 kGSSBumpPointerSpaceCapacity, nullptr); 335 CHECK(bump_pointer_space_ != nullptr); 336 AddSpace(bump_pointer_space_); 337 temp_space_ = space::BumpPointerSpace::Create("Bump pointer space 2", 338 kGSSBumpPointerSpaceCapacity, nullptr); 339 CHECK(temp_space_ != nullptr); 340 AddSpace(temp_space_); 341 } else if (main_mem_map_2.get() != nullptr) { 342 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 343 main_space_backup_.reset(CreateMallocSpaceFromMemMap(main_mem_map_2.release(), initial_size, 344 growth_limit_, capacity_, name, true)); 345 CHECK(main_space_backup_.get() != nullptr); 346 // Add the space so its accounted for in the heap_begin and heap_end. 347 AddSpace(main_space_backup_.get()); 348 } 349 } 350 CHECK(non_moving_space_ != nullptr); 351 CHECK(!non_moving_space_->CanMoveObjects()); 352 // Allocate the large object space. 353 if (large_object_space_type == space::kLargeObjectSpaceTypeFreeList) { 354 large_object_space_ = space::FreeListSpace::Create("free list large object space", nullptr, 355 capacity_); 356 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 357 } else if (large_object_space_type == space::kLargeObjectSpaceTypeMap) { 358 large_object_space_ = space::LargeObjectMapSpace::Create("mem map large object space"); 359 CHECK(large_object_space_ != nullptr) << "Failed to create large object space"; 360 } else { 361 // Disable the large object space by making the cutoff excessively large. 362 large_object_threshold_ = std::numeric_limits<size_t>::max(); 363 large_object_space_ = nullptr; 364 } 365 if (large_object_space_ != nullptr) { 366 AddSpace(large_object_space_); 367 } 368 // Compute heap capacity. Continuous spaces are sorted in order of Begin(). 369 CHECK(!continuous_spaces_.empty()); 370 // Relies on the spaces being sorted. 371 uint8_t* heap_begin = continuous_spaces_.front()->Begin(); 372 uint8_t* heap_end = continuous_spaces_.back()->Limit(); 373 size_t heap_capacity = heap_end - heap_begin; 374 // Remove the main backup space since it slows down the GC to have unused extra spaces. 375 // TODO: Avoid needing to do this. 376 if (main_space_backup_.get() != nullptr) { 377 RemoveSpace(main_space_backup_.get()); 378 } 379 // Allocate the card table. 380 card_table_.reset(accounting::CardTable::Create(heap_begin, heap_capacity)); 381 CHECK(card_table_.get() != NULL) << "Failed to create card table"; 382 // Card cache for now since it makes it easier for us to update the references to the copying 383 // spaces. 384 accounting::ModUnionTable* mod_union_table = 385 new accounting::ModUnionTableToZygoteAllocspace("Image mod-union table", this, 386 GetImageSpace()); 387 CHECK(mod_union_table != nullptr) << "Failed to create image mod-union table"; 388 AddModUnionTable(mod_union_table); 389 if (collector::SemiSpace::kUseRememberedSet && non_moving_space_ != main_space_) { 390 accounting::RememberedSet* non_moving_space_rem_set = 391 new accounting::RememberedSet("Non-moving space remembered set", this, non_moving_space_); 392 CHECK(non_moving_space_rem_set != nullptr) << "Failed to create non-moving space remembered set"; 393 AddRememberedSet(non_moving_space_rem_set); 394 } 395 // TODO: Count objects in the image space here? 396 num_bytes_allocated_.StoreRelaxed(0); 397 mark_stack_.reset(accounting::ObjectStack::Create("mark stack", kDefaultMarkStackSize, 398 kDefaultMarkStackSize)); 399 const size_t alloc_stack_capacity = max_allocation_stack_size_ + kAllocationStackReserveSize; 400 allocation_stack_.reset(accounting::ObjectStack::Create( 401 "allocation stack", max_allocation_stack_size_, alloc_stack_capacity)); 402 live_stack_.reset(accounting::ObjectStack::Create( 403 "live stack", max_allocation_stack_size_, alloc_stack_capacity)); 404 // It's still too early to take a lock because there are no threads yet, but we can create locks 405 // now. We don't create it earlier to make it clear that you can't use locks during heap 406 // initialization. 407 gc_complete_lock_ = new Mutex("GC complete lock"); 408 gc_complete_cond_.reset(new ConditionVariable("GC complete condition variable", 409 *gc_complete_lock_)); 410 task_processor_.reset(new TaskProcessor()); 411 pending_task_lock_ = new Mutex("Pending task lock"); 412 if (ignore_max_footprint_) { 413 SetIdealFootprint(std::numeric_limits<size_t>::max()); 414 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 415 } 416 CHECK_NE(max_allowed_footprint_, 0U); 417 // Create our garbage collectors. 418 for (size_t i = 0; i < 2; ++i) { 419 const bool concurrent = i != 0; 420 garbage_collectors_.push_back(new collector::MarkSweep(this, concurrent)); 421 garbage_collectors_.push_back(new collector::PartialMarkSweep(this, concurrent)); 422 garbage_collectors_.push_back(new collector::StickyMarkSweep(this, concurrent)); 423 } 424 if (kMovingCollector) { 425 // TODO: Clean this up. 426 const bool generational = foreground_collector_type_ == kCollectorTypeGSS; 427 semi_space_collector_ = new collector::SemiSpace(this, generational, 428 generational ? "generational" : ""); 429 garbage_collectors_.push_back(semi_space_collector_); 430 concurrent_copying_collector_ = new collector::ConcurrentCopying(this); 431 garbage_collectors_.push_back(concurrent_copying_collector_); 432 mark_compact_collector_ = new collector::MarkCompact(this); 433 garbage_collectors_.push_back(mark_compact_collector_); 434 } 435 if (GetImageSpace() != nullptr && non_moving_space_ != nullptr && 436 (is_zygote || separate_non_moving_space || foreground_collector_type_ == kCollectorTypeGSS)) { 437 // Check that there's no gap between the image space and the non moving space so that the 438 // immune region won't break (eg. due to a large object allocated in the gap). This is only 439 // required when we're the zygote or using GSS. 440 bool no_gap = MemMap::CheckNoGaps(GetImageSpace()->GetMemMap(), 441 non_moving_space_->GetMemMap()); 442 if (!no_gap) { 443 MemMap::DumpMaps(LOG(ERROR)); 444 LOG(FATAL) << "There's a gap between the image space and the main space"; 445 } 446 } 447 if (running_on_valgrind_) { 448 Runtime::Current()->GetInstrumentation()->InstrumentQuickAllocEntryPoints(); 449 } 450 if (VLOG_IS_ON(heap) || VLOG_IS_ON(startup)) { 451 LOG(INFO) << "Heap() exiting"; 452 } 453} 454 455MemMap* Heap::MapAnonymousPreferredAddress(const char* name, uint8_t* request_begin, 456 size_t capacity, std::string* out_error_str) { 457 while (true) { 458 MemMap* map = MemMap::MapAnonymous(name, request_begin, capacity, 459 PROT_READ | PROT_WRITE, true, out_error_str); 460 if (map != nullptr || request_begin == nullptr) { 461 return map; 462 } 463 // Retry a second time with no specified request begin. 464 request_begin = nullptr; 465 } 466 return nullptr; 467} 468 469space::MallocSpace* Heap::CreateMallocSpaceFromMemMap(MemMap* mem_map, size_t initial_size, 470 size_t growth_limit, size_t capacity, 471 const char* name, bool can_move_objects) { 472 space::MallocSpace* malloc_space = nullptr; 473 if (kUseRosAlloc) { 474 // Create rosalloc space. 475 malloc_space = space::RosAllocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 476 initial_size, growth_limit, capacity, 477 low_memory_mode_, can_move_objects); 478 } else { 479 malloc_space = space::DlMallocSpace::CreateFromMemMap(mem_map, name, kDefaultStartingSize, 480 initial_size, growth_limit, capacity, 481 can_move_objects); 482 } 483 if (collector::SemiSpace::kUseRememberedSet) { 484 accounting::RememberedSet* rem_set = 485 new accounting::RememberedSet(std::string(name) + " remembered set", this, malloc_space); 486 CHECK(rem_set != nullptr) << "Failed to create main space remembered set"; 487 AddRememberedSet(rem_set); 488 } 489 CHECK(malloc_space != nullptr) << "Failed to create " << name; 490 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 491 return malloc_space; 492} 493 494void Heap::CreateMainMallocSpace(MemMap* mem_map, size_t initial_size, size_t growth_limit, 495 size_t capacity) { 496 // Is background compaction is enabled? 497 bool can_move_objects = IsMovingGc(background_collector_type_) != 498 IsMovingGc(foreground_collector_type_) || use_homogeneous_space_compaction_for_oom_; 499 // If we are the zygote and don't yet have a zygote space, it means that the zygote fork will 500 // happen in the future. If this happens and we have kCompactZygote enabled we wish to compact 501 // from the main space to the zygote space. If background compaction is enabled, always pass in 502 // that we can move objets. 503 if (kCompactZygote && Runtime::Current()->IsZygote() && !can_move_objects) { 504 // After the zygote we want this to be false if we don't have background compaction enabled so 505 // that getting primitive array elements is faster. 506 // We never have homogeneous compaction with GSS and don't need a space with movable objects. 507 can_move_objects = !HasZygoteSpace() && foreground_collector_type_ != kCollectorTypeGSS; 508 } 509 if (collector::SemiSpace::kUseRememberedSet && main_space_ != nullptr) { 510 RemoveRememberedSet(main_space_); 511 } 512 const char* name = kUseRosAlloc ? kRosAllocSpaceName[0] : kDlMallocSpaceName[0]; 513 main_space_ = CreateMallocSpaceFromMemMap(mem_map, initial_size, growth_limit, capacity, name, 514 can_move_objects); 515 SetSpaceAsDefault(main_space_); 516 VLOG(heap) << "Created main space " << main_space_; 517} 518 519void Heap::ChangeAllocator(AllocatorType allocator) { 520 if (current_allocator_ != allocator) { 521 // These two allocators are only used internally and don't have any entrypoints. 522 CHECK_NE(allocator, kAllocatorTypeLOS); 523 CHECK_NE(allocator, kAllocatorTypeNonMoving); 524 current_allocator_ = allocator; 525 MutexLock mu(nullptr, *Locks::runtime_shutdown_lock_); 526 SetQuickAllocEntryPointsAllocator(current_allocator_); 527 Runtime::Current()->GetInstrumentation()->ResetQuickAllocEntryPoints(); 528 } 529} 530 531void Heap::DisableMovingGc() { 532 if (IsMovingGc(foreground_collector_type_)) { 533 foreground_collector_type_ = kCollectorTypeCMS; 534 } 535 if (IsMovingGc(background_collector_type_)) { 536 background_collector_type_ = foreground_collector_type_; 537 } 538 TransitionCollector(foreground_collector_type_); 539 ThreadList* tl = Runtime::Current()->GetThreadList(); 540 Thread* self = Thread::Current(); 541 ScopedThreadStateChange tsc(self, kSuspended); 542 tl->SuspendAll(); 543 // Something may have caused the transition to fail. 544 if (!IsMovingGc(collector_type_) && non_moving_space_ != main_space_) { 545 CHECK(main_space_ != nullptr); 546 // The allocation stack may have non movable objects in it. We need to flush it since the GC 547 // can't only handle marking allocation stack objects of one non moving space and one main 548 // space. 549 { 550 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 551 FlushAllocStack(); 552 } 553 main_space_->DisableMovingObjects(); 554 non_moving_space_ = main_space_; 555 CHECK(!non_moving_space_->CanMoveObjects()); 556 } 557 tl->ResumeAll(); 558} 559 560std::string Heap::SafeGetClassDescriptor(mirror::Class* klass) { 561 if (!IsValidContinuousSpaceObjectAddress(klass)) { 562 return StringPrintf("<non heap address klass %p>", klass); 563 } 564 mirror::Class* component_type = klass->GetComponentType<kVerifyNone>(); 565 if (IsValidContinuousSpaceObjectAddress(component_type) && klass->IsArrayClass<kVerifyNone>()) { 566 std::string result("["); 567 result += SafeGetClassDescriptor(component_type); 568 return result; 569 } else if (UNLIKELY(klass->IsPrimitive<kVerifyNone>())) { 570 return Primitive::Descriptor(klass->GetPrimitiveType<kVerifyNone>()); 571 } else if (UNLIKELY(klass->IsProxyClass<kVerifyNone>())) { 572 return Runtime::Current()->GetClassLinker()->GetDescriptorForProxy(klass); 573 } else { 574 mirror::DexCache* dex_cache = klass->GetDexCache<kVerifyNone>(); 575 if (!IsValidContinuousSpaceObjectAddress(dex_cache)) { 576 return StringPrintf("<non heap address dex_cache %p>", dex_cache); 577 } 578 const DexFile* dex_file = dex_cache->GetDexFile(); 579 uint16_t class_def_idx = klass->GetDexClassDefIndex(); 580 if (class_def_idx == DexFile::kDexNoIndex16) { 581 return "<class def not found>"; 582 } 583 const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx); 584 const DexFile::TypeId& type_id = dex_file->GetTypeId(class_def.class_idx_); 585 return dex_file->GetTypeDescriptor(type_id); 586 } 587} 588 589std::string Heap::SafePrettyTypeOf(mirror::Object* obj) { 590 if (obj == nullptr) { 591 return "null"; 592 } 593 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 594 if (klass == nullptr) { 595 return "(class=null)"; 596 } 597 std::string result(SafeGetClassDescriptor(klass)); 598 if (obj->IsClass()) { 599 result += "<" + SafeGetClassDescriptor(obj->AsClass<kVerifyNone>()) + ">"; 600 } 601 return result; 602} 603 604void Heap::DumpObject(std::ostream& stream, mirror::Object* obj) { 605 if (obj == nullptr) { 606 stream << "(obj=null)"; 607 return; 608 } 609 if (IsAligned<kObjectAlignment>(obj)) { 610 space::Space* space = nullptr; 611 // Don't use find space since it only finds spaces which actually contain objects instead of 612 // spaces which may contain objects (e.g. cleared bump pointer spaces). 613 for (const auto& cur_space : continuous_spaces_) { 614 if (cur_space->HasAddress(obj)) { 615 space = cur_space; 616 break; 617 } 618 } 619 // Unprotect all the spaces. 620 for (const auto& con_space : continuous_spaces_) { 621 mprotect(con_space->Begin(), con_space->Capacity(), PROT_READ | PROT_WRITE); 622 } 623 stream << "Object " << obj; 624 if (space != nullptr) { 625 stream << " in space " << *space; 626 } 627 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 628 stream << "\nclass=" << klass; 629 if (klass != nullptr) { 630 stream << " type= " << SafePrettyTypeOf(obj); 631 } 632 // Re-protect the address we faulted on. 633 mprotect(AlignDown(obj, kPageSize), kPageSize, PROT_NONE); 634 } 635} 636 637bool Heap::IsCompilingBoot() const { 638 if (!Runtime::Current()->IsCompiler()) { 639 return false; 640 } 641 for (const auto& space : continuous_spaces_) { 642 if (space->IsImageSpace() || space->IsZygoteSpace()) { 643 return false; 644 } 645 } 646 return true; 647} 648 649bool Heap::HasImageSpace() const { 650 for (const auto& space : continuous_spaces_) { 651 if (space->IsImageSpace()) { 652 return true; 653 } 654 } 655 return false; 656} 657 658void Heap::IncrementDisableMovingGC(Thread* self) { 659 // Need to do this holding the lock to prevent races where the GC is about to run / running when 660 // we attempt to disable it. 661 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 662 MutexLock mu(self, *gc_complete_lock_); 663 ++disable_moving_gc_count_; 664 if (IsMovingGc(collector_type_running_)) { 665 WaitForGcToCompleteLocked(kGcCauseDisableMovingGc, self); 666 } 667} 668 669void Heap::DecrementDisableMovingGC(Thread* self) { 670 MutexLock mu(self, *gc_complete_lock_); 671 CHECK_GE(disable_moving_gc_count_, 0U); 672 --disable_moving_gc_count_; 673} 674 675void Heap::UpdateProcessState(ProcessState process_state) { 676 if (process_state_ != process_state) { 677 process_state_ = process_state; 678 for (size_t i = 1; i <= kCollectorTransitionStressIterations; ++i) { 679 // Start at index 1 to avoid "is always false" warning. 680 // Have iteration 1 always transition the collector. 681 TransitionCollector((((i & 1) == 1) == (process_state_ == kProcessStateJankPerceptible)) 682 ? foreground_collector_type_ : background_collector_type_); 683 usleep(kCollectorTransitionStressWait); 684 } 685 if (process_state_ == kProcessStateJankPerceptible) { 686 // Transition back to foreground right away to prevent jank. 687 RequestCollectorTransition(foreground_collector_type_, 0); 688 } else { 689 // Don't delay for debug builds since we may want to stress test the GC. 690 // If background_collector_type_ is kCollectorTypeHomogeneousSpaceCompact then we have 691 // special handling which does a homogenous space compaction once but then doesn't transition 692 // the collector. 693 RequestCollectorTransition(background_collector_type_, 694 kIsDebugBuild ? 0 : kCollectorTransitionWait); 695 } 696 } 697} 698 699void Heap::CreateThreadPool() { 700 const size_t num_threads = std::max(parallel_gc_threads_, conc_gc_threads_); 701 if (num_threads != 0) { 702 thread_pool_.reset(new ThreadPool("Heap thread pool", num_threads)); 703 } 704} 705 706void Heap::VisitObjects(ObjectCallback callback, void* arg) { 707 Thread* self = Thread::Current(); 708 if (Locks::mutator_lock_->IsExclusiveHeld(self)) { 709 // Threads are already suspended. 710 VisitObjectsInternal(callback, arg); 711 } else if (IsGcConcurrent() && IsMovingGc(collector_type_)) { 712 // Concurrent moving GC. Suspend all threads and visit objects. 713 DCHECK_EQ(collector_type_, foreground_collector_type_); 714 DCHECK_EQ(foreground_collector_type_, background_collector_type_) 715 << "Assume no transition such that collector_type_ won't change"; 716 self->TransitionFromRunnableToSuspended(kWaitingForVisitObjects); 717 ThreadList* tl = Runtime::Current()->GetThreadList(); 718 tl->SuspendAll(); 719 VisitObjectsInternal(callback, arg); 720 tl->ResumeAll(); 721 self->TransitionFromSuspendedToRunnable(); 722 } else { 723 // GCs can move objects, so don't allow this. 724 ScopedAssertNoThreadSuspension ants(self, "Visiting objects"); 725 VisitObjectsInternal(callback, arg); 726 } 727} 728 729void Heap::VisitObjectsInternal(ObjectCallback callback, void* arg) { 730 if (bump_pointer_space_ != nullptr) { 731 // Visit objects in bump pointer space. 732 bump_pointer_space_->Walk(callback, arg); 733 } 734 // TODO: Switch to standard begin and end to use ranged a based loop. 735 for (mirror::Object** it = allocation_stack_->Begin(), **end = allocation_stack_->End(); 736 it < end; ++it) { 737 mirror::Object* obj = *it; 738 if (obj != nullptr && obj->GetClass() != nullptr) { 739 // Avoid the race condition caused by the object not yet being written into the allocation 740 // stack or the class not yet being written in the object. Or, if 741 // kUseThreadLocalAllocationStack, there can be nulls on the allocation stack. 742 callback(obj, arg); 743 } 744 } 745 { 746 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 747 GetLiveBitmap()->Walk(callback, arg); 748 } 749} 750 751void Heap::MarkAllocStackAsLive(accounting::ObjectStack* stack) { 752 space::ContinuousSpace* space1 = main_space_ != nullptr ? main_space_ : non_moving_space_; 753 space::ContinuousSpace* space2 = non_moving_space_; 754 // TODO: Generalize this to n bitmaps? 755 CHECK(space1 != nullptr); 756 CHECK(space2 != nullptr); 757 MarkAllocStack(space1->GetLiveBitmap(), space2->GetLiveBitmap(), 758 (large_object_space_ != nullptr ? large_object_space_->GetLiveBitmap() : nullptr), 759 stack); 760} 761 762void Heap::DeleteThreadPool() { 763 thread_pool_.reset(nullptr); 764} 765 766void Heap::AddSpace(space::Space* space) { 767 CHECK(space != nullptr); 768 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 769 if (space->IsContinuousSpace()) { 770 DCHECK(!space->IsDiscontinuousSpace()); 771 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 772 // Continuous spaces don't necessarily have bitmaps. 773 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 774 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 775 if (live_bitmap != nullptr) { 776 CHECK(mark_bitmap != nullptr); 777 live_bitmap_->AddContinuousSpaceBitmap(live_bitmap); 778 mark_bitmap_->AddContinuousSpaceBitmap(mark_bitmap); 779 } 780 continuous_spaces_.push_back(continuous_space); 781 // Ensure that spaces remain sorted in increasing order of start address. 782 std::sort(continuous_spaces_.begin(), continuous_spaces_.end(), 783 [](const space::ContinuousSpace* a, const space::ContinuousSpace* b) { 784 return a->Begin() < b->Begin(); 785 }); 786 } else { 787 CHECK(space->IsDiscontinuousSpace()); 788 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 789 live_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 790 mark_bitmap_->AddLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 791 discontinuous_spaces_.push_back(discontinuous_space); 792 } 793 if (space->IsAllocSpace()) { 794 alloc_spaces_.push_back(space->AsAllocSpace()); 795 } 796} 797 798void Heap::SetSpaceAsDefault(space::ContinuousSpace* continuous_space) { 799 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 800 if (continuous_space->IsDlMallocSpace()) { 801 dlmalloc_space_ = continuous_space->AsDlMallocSpace(); 802 } else if (continuous_space->IsRosAllocSpace()) { 803 rosalloc_space_ = continuous_space->AsRosAllocSpace(); 804 } 805} 806 807void Heap::RemoveSpace(space::Space* space) { 808 DCHECK(space != nullptr); 809 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 810 if (space->IsContinuousSpace()) { 811 DCHECK(!space->IsDiscontinuousSpace()); 812 space::ContinuousSpace* continuous_space = space->AsContinuousSpace(); 813 // Continuous spaces don't necessarily have bitmaps. 814 accounting::ContinuousSpaceBitmap* live_bitmap = continuous_space->GetLiveBitmap(); 815 accounting::ContinuousSpaceBitmap* mark_bitmap = continuous_space->GetMarkBitmap(); 816 if (live_bitmap != nullptr) { 817 DCHECK(mark_bitmap != nullptr); 818 live_bitmap_->RemoveContinuousSpaceBitmap(live_bitmap); 819 mark_bitmap_->RemoveContinuousSpaceBitmap(mark_bitmap); 820 } 821 auto it = std::find(continuous_spaces_.begin(), continuous_spaces_.end(), continuous_space); 822 DCHECK(it != continuous_spaces_.end()); 823 continuous_spaces_.erase(it); 824 } else { 825 DCHECK(space->IsDiscontinuousSpace()); 826 space::DiscontinuousSpace* discontinuous_space = space->AsDiscontinuousSpace(); 827 live_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetLiveBitmap()); 828 mark_bitmap_->RemoveLargeObjectBitmap(discontinuous_space->GetMarkBitmap()); 829 auto it = std::find(discontinuous_spaces_.begin(), discontinuous_spaces_.end(), 830 discontinuous_space); 831 DCHECK(it != discontinuous_spaces_.end()); 832 discontinuous_spaces_.erase(it); 833 } 834 if (space->IsAllocSpace()) { 835 auto it = std::find(alloc_spaces_.begin(), alloc_spaces_.end(), space->AsAllocSpace()); 836 DCHECK(it != alloc_spaces_.end()); 837 alloc_spaces_.erase(it); 838 } 839} 840 841void Heap::DumpGcPerformanceInfo(std::ostream& os) { 842 // Dump cumulative timings. 843 os << "Dumping cumulative Gc timings\n"; 844 uint64_t total_duration = 0; 845 // Dump cumulative loggers for each GC type. 846 uint64_t total_paused_time = 0; 847 for (auto& collector : garbage_collectors_) { 848 total_duration += collector->GetCumulativeTimings().GetTotalNs(); 849 total_paused_time += collector->GetTotalPausedTimeNs(); 850 collector->DumpPerformanceInfo(os); 851 collector->ResetMeasurements(); 852 } 853 uint64_t allocation_time = 854 static_cast<uint64_t>(total_allocation_time_.LoadRelaxed()) * kTimeAdjust; 855 if (total_duration != 0) { 856 const double total_seconds = static_cast<double>(total_duration / 1000) / 1000000.0; 857 os << "Total time spent in GC: " << PrettyDuration(total_duration) << "\n"; 858 os << "Mean GC size throughput: " 859 << PrettySize(GetBytesFreedEver() / total_seconds) << "/s\n"; 860 os << "Mean GC object throughput: " 861 << (GetObjectsFreedEver() / total_seconds) << " objects/s\n"; 862 } 863 uint64_t total_objects_allocated = GetObjectsAllocatedEver(); 864 os << "Total number of allocations " << total_objects_allocated << "\n"; 865 uint64_t total_bytes_allocated = GetBytesAllocatedEver(); 866 os << "Total bytes allocated " << PrettySize(total_bytes_allocated) << "\n"; 867 os << "Free memory " << PrettySize(GetFreeMemory()) << "\n"; 868 os << "Free memory until GC " << PrettySize(GetFreeMemoryUntilGC()) << "\n"; 869 os << "Free memory until OOME " << PrettySize(GetFreeMemoryUntilOOME()) << "\n"; 870 os << "Total memory " << PrettySize(GetTotalMemory()) << "\n"; 871 os << "Max memory " << PrettySize(GetMaxMemory()) << "\n"; 872 if (kMeasureAllocationTime) { 873 os << "Total time spent allocating: " << PrettyDuration(allocation_time) << "\n"; 874 os << "Mean allocation time: " << PrettyDuration(allocation_time / total_objects_allocated) 875 << "\n"; 876 } 877 if (HasZygoteSpace()) { 878 os << "Zygote space size " << PrettySize(zygote_space_->Size()) << "\n"; 879 } 880 os << "Total mutator paused time: " << PrettyDuration(total_paused_time) << "\n"; 881 os << "Total time waiting for GC to complete: " << PrettyDuration(total_wait_time_); 882 BaseMutex::DumpAll(os); 883} 884 885Heap::~Heap() { 886 VLOG(heap) << "Starting ~Heap()"; 887 STLDeleteElements(&garbage_collectors_); 888 // If we don't reset then the mark stack complains in its destructor. 889 allocation_stack_->Reset(); 890 live_stack_->Reset(); 891 STLDeleteValues(&mod_union_tables_); 892 STLDeleteValues(&remembered_sets_); 893 STLDeleteElements(&continuous_spaces_); 894 STLDeleteElements(&discontinuous_spaces_); 895 delete gc_complete_lock_; 896 delete pending_task_lock_; 897 VLOG(heap) << "Finished ~Heap()"; 898} 899 900space::ContinuousSpace* Heap::FindContinuousSpaceFromObject(const mirror::Object* obj, 901 bool fail_ok) const { 902 for (const auto& space : continuous_spaces_) { 903 if (space->Contains(obj)) { 904 return space; 905 } 906 } 907 if (!fail_ok) { 908 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 909 } 910 return NULL; 911} 912 913space::DiscontinuousSpace* Heap::FindDiscontinuousSpaceFromObject(const mirror::Object* obj, 914 bool fail_ok) const { 915 for (const auto& space : discontinuous_spaces_) { 916 if (space->Contains(obj)) { 917 return space; 918 } 919 } 920 if (!fail_ok) { 921 LOG(FATAL) << "object " << reinterpret_cast<const void*>(obj) << " not inside any spaces!"; 922 } 923 return NULL; 924} 925 926space::Space* Heap::FindSpaceFromObject(const mirror::Object* obj, bool fail_ok) const { 927 space::Space* result = FindContinuousSpaceFromObject(obj, true); 928 if (result != NULL) { 929 return result; 930 } 931 return FindDiscontinuousSpaceFromObject(obj, fail_ok); 932} 933 934space::ImageSpace* Heap::GetImageSpace() const { 935 for (const auto& space : continuous_spaces_) { 936 if (space->IsImageSpace()) { 937 return space->AsImageSpace(); 938 } 939 } 940 return NULL; 941} 942 943void Heap::ThrowOutOfMemoryError(Thread* self, size_t byte_count, AllocatorType allocator_type) { 944 std::ostringstream oss; 945 size_t total_bytes_free = GetFreeMemory(); 946 oss << "Failed to allocate a " << byte_count << " byte allocation with " << total_bytes_free 947 << " free bytes and " << PrettySize(GetFreeMemoryUntilOOME()) << " until OOM"; 948 // If the allocation failed due to fragmentation, print out the largest continuous allocation. 949 if (total_bytes_free >= byte_count) { 950 space::AllocSpace* space = nullptr; 951 if (allocator_type == kAllocatorTypeNonMoving) { 952 space = non_moving_space_; 953 } else if (allocator_type == kAllocatorTypeRosAlloc || 954 allocator_type == kAllocatorTypeDlMalloc) { 955 space = main_space_; 956 } else if (allocator_type == kAllocatorTypeBumpPointer || 957 allocator_type == kAllocatorTypeTLAB) { 958 space = bump_pointer_space_; 959 } 960 if (space != nullptr) { 961 space->LogFragmentationAllocFailure(oss, byte_count); 962 } 963 } 964 self->ThrowOutOfMemoryError(oss.str().c_str()); 965} 966 967void Heap::DoPendingCollectorTransition() { 968 CollectorType desired_collector_type = desired_collector_type_; 969 // Launch homogeneous space compaction if it is desired. 970 if (desired_collector_type == kCollectorTypeHomogeneousSpaceCompact) { 971 if (!CareAboutPauseTimes()) { 972 PerformHomogeneousSpaceCompact(); 973 } else { 974 VLOG(gc) << "Homogeneous compaction ignored due to jank perceptible process state"; 975 } 976 } else { 977 TransitionCollector(desired_collector_type); 978 } 979} 980 981void Heap::Trim(Thread* self) { 982 if (!CareAboutPauseTimes()) { 983 ATRACE_BEGIN("Deflating monitors"); 984 // Deflate the monitors, this can cause a pause but shouldn't matter since we don't care 985 // about pauses. 986 Runtime* runtime = Runtime::Current(); 987 runtime->GetThreadList()->SuspendAll(); 988 uint64_t start_time = NanoTime(); 989 size_t count = runtime->GetMonitorList()->DeflateMonitors(); 990 VLOG(heap) << "Deflating " << count << " monitors took " 991 << PrettyDuration(NanoTime() - start_time); 992 runtime->GetThreadList()->ResumeAll(); 993 ATRACE_END(); 994 } 995 TrimIndirectReferenceTables(self); 996 TrimSpaces(self); 997} 998 999class TrimIndirectReferenceTableClosure : public Closure { 1000 public: 1001 explicit TrimIndirectReferenceTableClosure(Barrier* barrier) : barrier_(barrier) { 1002 } 1003 virtual void Run(Thread* thread) OVERRIDE NO_THREAD_SAFETY_ANALYSIS { 1004 ATRACE_BEGIN("Trimming reference table"); 1005 thread->GetJniEnv()->locals.Trim(); 1006 ATRACE_END(); 1007 barrier_->Pass(Thread::Current()); 1008 } 1009 1010 private: 1011 Barrier* const barrier_; 1012}; 1013 1014void Heap::TrimIndirectReferenceTables(Thread* self) { 1015 ScopedObjectAccess soa(self); 1016 ATRACE_BEGIN(__FUNCTION__); 1017 JavaVMExt* vm = soa.Vm(); 1018 // Trim globals indirect reference table. 1019 vm->TrimGlobals(); 1020 // Trim locals indirect reference tables. 1021 Barrier barrier(0); 1022 TrimIndirectReferenceTableClosure closure(&barrier); 1023 ScopedThreadStateChange tsc(self, kWaitingForCheckPointsToRun); 1024 size_t barrier_count = Runtime::Current()->GetThreadList()->RunCheckpoint(&closure); 1025 barrier.Increment(self, barrier_count); 1026 ATRACE_END(); 1027} 1028 1029void Heap::TrimSpaces(Thread* self) { 1030 { 1031 // Need to do this before acquiring the locks since we don't want to get suspended while 1032 // holding any locks. 1033 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 1034 // Pretend we are doing a GC to prevent background compaction from deleting the space we are 1035 // trimming. 1036 MutexLock mu(self, *gc_complete_lock_); 1037 // Ensure there is only one GC at a time. 1038 WaitForGcToCompleteLocked(kGcCauseTrim, self); 1039 collector_type_running_ = kCollectorTypeHeapTrim; 1040 } 1041 ATRACE_BEGIN(__FUNCTION__); 1042 const uint64_t start_ns = NanoTime(); 1043 // Trim the managed spaces. 1044 uint64_t total_alloc_space_allocated = 0; 1045 uint64_t total_alloc_space_size = 0; 1046 uint64_t managed_reclaimed = 0; 1047 for (const auto& space : continuous_spaces_) { 1048 if (space->IsMallocSpace()) { 1049 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 1050 if (malloc_space->IsRosAllocSpace() || !CareAboutPauseTimes()) { 1051 // Don't trim dlmalloc spaces if we care about pauses since this can hold the space lock 1052 // for a long period of time. 1053 managed_reclaimed += malloc_space->Trim(); 1054 } 1055 total_alloc_space_size += malloc_space->Size(); 1056 } 1057 } 1058 total_alloc_space_allocated = GetBytesAllocated(); 1059 if (large_object_space_ != nullptr) { 1060 total_alloc_space_allocated -= large_object_space_->GetBytesAllocated(); 1061 } 1062 if (bump_pointer_space_ != nullptr) { 1063 total_alloc_space_allocated -= bump_pointer_space_->Size(); 1064 } 1065 const float managed_utilization = static_cast<float>(total_alloc_space_allocated) / 1066 static_cast<float>(total_alloc_space_size); 1067 uint64_t gc_heap_end_ns = NanoTime(); 1068 // We never move things in the native heap, so we can finish the GC at this point. 1069 FinishGC(self, collector::kGcTypeNone); 1070 size_t native_reclaimed = 0; 1071 1072#ifdef HAVE_ANDROID_OS 1073 // Only trim the native heap if we don't care about pauses. 1074 if (!CareAboutPauseTimes()) { 1075#if defined(USE_DLMALLOC) 1076 // Trim the native heap. 1077 dlmalloc_trim(0); 1078 dlmalloc_inspect_all(DlmallocMadviseCallback, &native_reclaimed); 1079#elif defined(USE_JEMALLOC) 1080 // Jemalloc does it's own internal trimming. 1081#else 1082 UNIMPLEMENTED(WARNING) << "Add trimming support"; 1083#endif 1084 } 1085#endif // HAVE_ANDROID_OS 1086 uint64_t end_ns = NanoTime(); 1087 VLOG(heap) << "Heap trim of managed (duration=" << PrettyDuration(gc_heap_end_ns - start_ns) 1088 << ", advised=" << PrettySize(managed_reclaimed) << ") and native (duration=" 1089 << PrettyDuration(end_ns - gc_heap_end_ns) << ", advised=" << PrettySize(native_reclaimed) 1090 << ") heaps. Managed heap utilization of " << static_cast<int>(100 * managed_utilization) 1091 << "%."; 1092 ATRACE_END(); 1093} 1094 1095bool Heap::IsValidObjectAddress(const mirror::Object* obj) const { 1096 // Note: we deliberately don't take the lock here, and mustn't test anything that would require 1097 // taking the lock. 1098 if (obj == nullptr) { 1099 return true; 1100 } 1101 return IsAligned<kObjectAlignment>(obj) && FindSpaceFromObject(obj, true) != nullptr; 1102} 1103 1104bool Heap::IsNonDiscontinuousSpaceHeapAddress(const mirror::Object* obj) const { 1105 return FindContinuousSpaceFromObject(obj, true) != nullptr; 1106} 1107 1108bool Heap::IsValidContinuousSpaceObjectAddress(const mirror::Object* obj) const { 1109 if (obj == nullptr || !IsAligned<kObjectAlignment>(obj)) { 1110 return false; 1111 } 1112 for (const auto& space : continuous_spaces_) { 1113 if (space->HasAddress(obj)) { 1114 return true; 1115 } 1116 } 1117 return false; 1118} 1119 1120bool Heap::IsLiveObjectLocked(mirror::Object* obj, bool search_allocation_stack, 1121 bool search_live_stack, bool sorted) { 1122 if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) { 1123 return false; 1124 } 1125 if (bump_pointer_space_ != nullptr && bump_pointer_space_->HasAddress(obj)) { 1126 mirror::Class* klass = obj->GetClass<kVerifyNone>(); 1127 if (obj == klass) { 1128 // This case happens for java.lang.Class. 1129 return true; 1130 } 1131 return VerifyClassClass(klass) && IsLiveObjectLocked(klass); 1132 } else if (temp_space_ != nullptr && temp_space_->HasAddress(obj)) { 1133 // If we are in the allocated region of the temp space, then we are probably live (e.g. during 1134 // a GC). When a GC isn't running End() - Begin() is 0 which means no objects are contained. 1135 return temp_space_->Contains(obj); 1136 } 1137 space::ContinuousSpace* c_space = FindContinuousSpaceFromObject(obj, true); 1138 space::DiscontinuousSpace* d_space = nullptr; 1139 if (c_space != nullptr) { 1140 if (c_space->GetLiveBitmap()->Test(obj)) { 1141 return true; 1142 } 1143 } else { 1144 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1145 if (d_space != nullptr) { 1146 if (d_space->GetLiveBitmap()->Test(obj)) { 1147 return true; 1148 } 1149 } 1150 } 1151 // This is covering the allocation/live stack swapping that is done without mutators suspended. 1152 for (size_t i = 0; i < (sorted ? 1 : 5); ++i) { 1153 if (i > 0) { 1154 NanoSleep(MsToNs(10)); 1155 } 1156 if (search_allocation_stack) { 1157 if (sorted) { 1158 if (allocation_stack_->ContainsSorted(obj)) { 1159 return true; 1160 } 1161 } else if (allocation_stack_->Contains(obj)) { 1162 return true; 1163 } 1164 } 1165 1166 if (search_live_stack) { 1167 if (sorted) { 1168 if (live_stack_->ContainsSorted(obj)) { 1169 return true; 1170 } 1171 } else if (live_stack_->Contains(obj)) { 1172 return true; 1173 } 1174 } 1175 } 1176 // We need to check the bitmaps again since there is a race where we mark something as live and 1177 // then clear the stack containing it. 1178 if (c_space != nullptr) { 1179 if (c_space->GetLiveBitmap()->Test(obj)) { 1180 return true; 1181 } 1182 } else { 1183 d_space = FindDiscontinuousSpaceFromObject(obj, true); 1184 if (d_space != nullptr && d_space->GetLiveBitmap()->Test(obj)) { 1185 return true; 1186 } 1187 } 1188 return false; 1189} 1190 1191std::string Heap::DumpSpaces() const { 1192 std::ostringstream oss; 1193 DumpSpaces(oss); 1194 return oss.str(); 1195} 1196 1197void Heap::DumpSpaces(std::ostream& stream) const { 1198 for (const auto& space : continuous_spaces_) { 1199 accounting::ContinuousSpaceBitmap* live_bitmap = space->GetLiveBitmap(); 1200 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 1201 stream << space << " " << *space << "\n"; 1202 if (live_bitmap != nullptr) { 1203 stream << live_bitmap << " " << *live_bitmap << "\n"; 1204 } 1205 if (mark_bitmap != nullptr) { 1206 stream << mark_bitmap << " " << *mark_bitmap << "\n"; 1207 } 1208 } 1209 for (const auto& space : discontinuous_spaces_) { 1210 stream << space << " " << *space << "\n"; 1211 } 1212} 1213 1214void Heap::VerifyObjectBody(mirror::Object* obj) { 1215 if (verify_object_mode_ == kVerifyObjectModeDisabled) { 1216 return; 1217 } 1218 1219 // Ignore early dawn of the universe verifications. 1220 if (UNLIKELY(static_cast<size_t>(num_bytes_allocated_.LoadRelaxed()) < 10 * KB)) { 1221 return; 1222 } 1223 CHECK(IsAligned<kObjectAlignment>(obj)) << "Object isn't aligned: " << obj; 1224 mirror::Class* c = obj->GetFieldObject<mirror::Class, kVerifyNone>(mirror::Object::ClassOffset()); 1225 CHECK(c != nullptr) << "Null class in object " << obj; 1226 CHECK(IsAligned<kObjectAlignment>(c)) << "Class " << c << " not aligned in object " << obj; 1227 CHECK(VerifyClassClass(c)); 1228 1229 if (verify_object_mode_ > kVerifyObjectModeFast) { 1230 // Note: the bitmap tests below are racy since we don't hold the heap bitmap lock. 1231 CHECK(IsLiveObjectLocked(obj)) << "Object is dead " << obj << "\n" << DumpSpaces(); 1232 } 1233} 1234 1235void Heap::VerificationCallback(mirror::Object* obj, void* arg) { 1236 reinterpret_cast<Heap*>(arg)->VerifyObjectBody(obj); 1237} 1238 1239void Heap::VerifyHeap() { 1240 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1241 GetLiveBitmap()->Walk(Heap::VerificationCallback, this); 1242} 1243 1244void Heap::RecordFree(uint64_t freed_objects, int64_t freed_bytes) { 1245 // Use signed comparison since freed bytes can be negative when background compaction foreground 1246 // transitions occurs. This is caused by the moving objects from a bump pointer space to a 1247 // free list backed space typically increasing memory footprint due to padding and binning. 1248 DCHECK_LE(freed_bytes, static_cast<int64_t>(num_bytes_allocated_.LoadRelaxed())); 1249 // Note: This relies on 2s complement for handling negative freed_bytes. 1250 num_bytes_allocated_.FetchAndSubSequentiallyConsistent(static_cast<ssize_t>(freed_bytes)); 1251 if (Runtime::Current()->HasStatsEnabled()) { 1252 RuntimeStats* thread_stats = Thread::Current()->GetStats(); 1253 thread_stats->freed_objects += freed_objects; 1254 thread_stats->freed_bytes += freed_bytes; 1255 // TODO: Do this concurrently. 1256 RuntimeStats* global_stats = Runtime::Current()->GetStats(); 1257 global_stats->freed_objects += freed_objects; 1258 global_stats->freed_bytes += freed_bytes; 1259 } 1260} 1261 1262space::RosAllocSpace* Heap::GetRosAllocSpace(gc::allocator::RosAlloc* rosalloc) const { 1263 for (const auto& space : continuous_spaces_) { 1264 if (space->AsContinuousSpace()->IsRosAllocSpace()) { 1265 if (space->AsContinuousSpace()->AsRosAllocSpace()->GetRosAlloc() == rosalloc) { 1266 return space->AsContinuousSpace()->AsRosAllocSpace(); 1267 } 1268 } 1269 } 1270 return nullptr; 1271} 1272 1273mirror::Object* Heap::AllocateInternalWithGc(Thread* self, AllocatorType allocator, 1274 size_t alloc_size, size_t* bytes_allocated, 1275 size_t* usable_size, 1276 mirror::Class** klass) { 1277 bool was_default_allocator = allocator == GetCurrentAllocator(); 1278 // Make sure there is no pending exception since we may need to throw an OOME. 1279 self->AssertNoPendingException(); 1280 DCHECK(klass != nullptr); 1281 StackHandleScope<1> hs(self); 1282 HandleWrapper<mirror::Class> h(hs.NewHandleWrapper(klass)); 1283 klass = nullptr; // Invalidate for safety. 1284 // The allocation failed. If the GC is running, block until it completes, and then retry the 1285 // allocation. 1286 collector::GcType last_gc = WaitForGcToComplete(kGcCauseForAlloc, self); 1287 if (last_gc != collector::kGcTypeNone) { 1288 // If we were the default allocator but the allocator changed while we were suspended, 1289 // abort the allocation. 1290 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1291 return nullptr; 1292 } 1293 // A GC was in progress and we blocked, retry allocation now that memory has been freed. 1294 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1295 usable_size); 1296 if (ptr != nullptr) { 1297 return ptr; 1298 } 1299 } 1300 1301 collector::GcType tried_type = next_gc_type_; 1302 const bool gc_ran = 1303 CollectGarbageInternal(tried_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1304 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1305 return nullptr; 1306 } 1307 if (gc_ran) { 1308 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1309 usable_size); 1310 if (ptr != nullptr) { 1311 return ptr; 1312 } 1313 } 1314 1315 // Loop through our different Gc types and try to Gc until we get enough free memory. 1316 for (collector::GcType gc_type : gc_plan_) { 1317 if (gc_type == tried_type) { 1318 continue; 1319 } 1320 // Attempt to run the collector, if we succeed, re-try the allocation. 1321 const bool plan_gc_ran = 1322 CollectGarbageInternal(gc_type, kGcCauseForAlloc, false) != collector::kGcTypeNone; 1323 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1324 return nullptr; 1325 } 1326 if (plan_gc_ran) { 1327 // Did we free sufficient memory for the allocation to succeed? 1328 mirror::Object* ptr = TryToAllocate<true, false>(self, allocator, alloc_size, bytes_allocated, 1329 usable_size); 1330 if (ptr != nullptr) { 1331 return ptr; 1332 } 1333 } 1334 } 1335 // Allocations have failed after GCs; this is an exceptional state. 1336 // Try harder, growing the heap if necessary. 1337 mirror::Object* ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1338 usable_size); 1339 if (ptr != nullptr) { 1340 return ptr; 1341 } 1342 // Most allocations should have succeeded by now, so the heap is really full, really fragmented, 1343 // or the requested size is really big. Do another GC, collecting SoftReferences this time. The 1344 // VM spec requires that all SoftReferences have been collected and cleared before throwing 1345 // OOME. 1346 VLOG(gc) << "Forcing collection of SoftReferences for " << PrettySize(alloc_size) 1347 << " allocation"; 1348 // TODO: Run finalization, but this may cause more allocations to occur. 1349 // We don't need a WaitForGcToComplete here either. 1350 DCHECK(!gc_plan_.empty()); 1351 CollectGarbageInternal(gc_plan_.back(), kGcCauseForAlloc, true); 1352 if (was_default_allocator && allocator != GetCurrentAllocator()) { 1353 return nullptr; 1354 } 1355 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, usable_size); 1356 if (ptr == nullptr) { 1357 const uint64_t current_time = NanoTime(); 1358 switch (allocator) { 1359 case kAllocatorTypeRosAlloc: 1360 // Fall-through. 1361 case kAllocatorTypeDlMalloc: { 1362 if (use_homogeneous_space_compaction_for_oom_ && 1363 current_time - last_time_homogeneous_space_compaction_by_oom_ > 1364 min_interval_homogeneous_space_compaction_by_oom_) { 1365 last_time_homogeneous_space_compaction_by_oom_ = current_time; 1366 HomogeneousSpaceCompactResult result = PerformHomogeneousSpaceCompact(); 1367 switch (result) { 1368 case HomogeneousSpaceCompactResult::kSuccess: 1369 // If the allocation succeeded, we delayed an oom. 1370 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1371 usable_size); 1372 if (ptr != nullptr) { 1373 count_delayed_oom_++; 1374 } 1375 break; 1376 case HomogeneousSpaceCompactResult::kErrorReject: 1377 // Reject due to disabled moving GC. 1378 break; 1379 case HomogeneousSpaceCompactResult::kErrorVMShuttingDown: 1380 // Throw OOM by default. 1381 break; 1382 default: { 1383 UNIMPLEMENTED(FATAL) << "homogeneous space compaction result: " 1384 << static_cast<size_t>(result); 1385 UNREACHABLE(); 1386 } 1387 } 1388 // Always print that we ran homogeneous space compation since this can cause jank. 1389 VLOG(heap) << "Ran heap homogeneous space compaction, " 1390 << " requested defragmentation " 1391 << count_requested_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1392 << " performed defragmentation " 1393 << count_performed_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1394 << " ignored homogeneous space compaction " 1395 << count_ignored_homogeneous_space_compaction_.LoadSequentiallyConsistent() 1396 << " delayed count = " 1397 << count_delayed_oom_.LoadSequentiallyConsistent(); 1398 } 1399 break; 1400 } 1401 case kAllocatorTypeNonMoving: { 1402 // Try to transition the heap if the allocation failure was due to the space being full. 1403 if (!IsOutOfMemoryOnAllocation<false>(allocator, alloc_size)) { 1404 // If we aren't out of memory then the OOM was probably from the non moving space being 1405 // full. Attempt to disable compaction and turn the main space into a non moving space. 1406 DisableMovingGc(); 1407 // If we are still a moving GC then something must have caused the transition to fail. 1408 if (IsMovingGc(collector_type_)) { 1409 MutexLock mu(self, *gc_complete_lock_); 1410 // If we couldn't disable moving GC, just throw OOME and return null. 1411 LOG(WARNING) << "Couldn't disable moving GC with disable GC count " 1412 << disable_moving_gc_count_; 1413 } else { 1414 LOG(WARNING) << "Disabled moving GC due to the non moving space being full"; 1415 ptr = TryToAllocate<true, true>(self, allocator, alloc_size, bytes_allocated, 1416 usable_size); 1417 } 1418 } 1419 break; 1420 } 1421 default: { 1422 // Do nothing for others allocators. 1423 } 1424 } 1425 } 1426 // If the allocation hasn't succeeded by this point, throw an OOM error. 1427 if (ptr == nullptr) { 1428 ThrowOutOfMemoryError(self, alloc_size, allocator); 1429 } 1430 return ptr; 1431} 1432 1433void Heap::SetTargetHeapUtilization(float target) { 1434 DCHECK_GT(target, 0.0f); // asserted in Java code 1435 DCHECK_LT(target, 1.0f); 1436 target_utilization_ = target; 1437} 1438 1439size_t Heap::GetObjectsAllocated() const { 1440 size_t total = 0; 1441 for (space::AllocSpace* space : alloc_spaces_) { 1442 total += space->GetObjectsAllocated(); 1443 } 1444 return total; 1445} 1446 1447uint64_t Heap::GetObjectsAllocatedEver() const { 1448 return GetObjectsFreedEver() + GetObjectsAllocated(); 1449} 1450 1451uint64_t Heap::GetBytesAllocatedEver() const { 1452 return GetBytesFreedEver() + GetBytesAllocated(); 1453} 1454 1455class InstanceCounter { 1456 public: 1457 InstanceCounter(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, uint64_t* counts) 1458 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1459 : classes_(classes), use_is_assignable_from_(use_is_assignable_from), counts_(counts) { 1460 } 1461 static void Callback(mirror::Object* obj, void* arg) 1462 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1463 InstanceCounter* instance_counter = reinterpret_cast<InstanceCounter*>(arg); 1464 mirror::Class* instance_class = obj->GetClass(); 1465 CHECK(instance_class != nullptr); 1466 for (size_t i = 0; i < instance_counter->classes_.size(); ++i) { 1467 if (instance_counter->use_is_assignable_from_) { 1468 if (instance_counter->classes_[i]->IsAssignableFrom(instance_class)) { 1469 ++instance_counter->counts_[i]; 1470 } 1471 } else if (instance_class == instance_counter->classes_[i]) { 1472 ++instance_counter->counts_[i]; 1473 } 1474 } 1475 } 1476 1477 private: 1478 const std::vector<mirror::Class*>& classes_; 1479 bool use_is_assignable_from_; 1480 uint64_t* const counts_; 1481 DISALLOW_COPY_AND_ASSIGN(InstanceCounter); 1482}; 1483 1484void Heap::CountInstances(const std::vector<mirror::Class*>& classes, bool use_is_assignable_from, 1485 uint64_t* counts) { 1486 InstanceCounter counter(classes, use_is_assignable_from, counts); 1487 VisitObjects(InstanceCounter::Callback, &counter); 1488} 1489 1490class InstanceCollector { 1491 public: 1492 InstanceCollector(mirror::Class* c, int32_t max_count, std::vector<mirror::Object*>& instances) 1493 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1494 : class_(c), max_count_(max_count), instances_(instances) { 1495 } 1496 static void Callback(mirror::Object* obj, void* arg) 1497 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1498 DCHECK(arg != nullptr); 1499 InstanceCollector* instance_collector = reinterpret_cast<InstanceCollector*>(arg); 1500 if (obj->GetClass() == instance_collector->class_) { 1501 if (instance_collector->max_count_ == 0 || 1502 instance_collector->instances_.size() < instance_collector->max_count_) { 1503 instance_collector->instances_.push_back(obj); 1504 } 1505 } 1506 } 1507 1508 private: 1509 const mirror::Class* const class_; 1510 const uint32_t max_count_; 1511 std::vector<mirror::Object*>& instances_; 1512 DISALLOW_COPY_AND_ASSIGN(InstanceCollector); 1513}; 1514 1515void Heap::GetInstances(mirror::Class* c, int32_t max_count, 1516 std::vector<mirror::Object*>& instances) { 1517 InstanceCollector collector(c, max_count, instances); 1518 VisitObjects(&InstanceCollector::Callback, &collector); 1519} 1520 1521class ReferringObjectsFinder { 1522 public: 1523 ReferringObjectsFinder(mirror::Object* object, int32_t max_count, 1524 std::vector<mirror::Object*>& referring_objects) 1525 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 1526 : object_(object), max_count_(max_count), referring_objects_(referring_objects) { 1527 } 1528 1529 static void Callback(mirror::Object* obj, void* arg) 1530 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 1531 reinterpret_cast<ReferringObjectsFinder*>(arg)->operator()(obj); 1532 } 1533 1534 // For bitmap Visit. 1535 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 1536 // annotalysis on visitors. 1537 void operator()(mirror::Object* o) const NO_THREAD_SAFETY_ANALYSIS { 1538 o->VisitReferences<true>(*this, VoidFunctor()); 1539 } 1540 1541 // For Object::VisitReferences. 1542 void operator()(mirror::Object* obj, MemberOffset offset, bool /* is_static */) const 1543 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1544 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 1545 if (ref == object_ && (max_count_ == 0 || referring_objects_.size() < max_count_)) { 1546 referring_objects_.push_back(obj); 1547 } 1548 } 1549 1550 private: 1551 const mirror::Object* const object_; 1552 const uint32_t max_count_; 1553 std::vector<mirror::Object*>& referring_objects_; 1554 DISALLOW_COPY_AND_ASSIGN(ReferringObjectsFinder); 1555}; 1556 1557void Heap::GetReferringObjects(mirror::Object* o, int32_t max_count, 1558 std::vector<mirror::Object*>& referring_objects) { 1559 ReferringObjectsFinder finder(o, max_count, referring_objects); 1560 VisitObjects(&ReferringObjectsFinder::Callback, &finder); 1561} 1562 1563void Heap::CollectGarbage(bool clear_soft_references) { 1564 // Even if we waited for a GC we still need to do another GC since weaks allocated during the 1565 // last GC will not have necessarily been cleared. 1566 CollectGarbageInternal(gc_plan_.back(), kGcCauseExplicit, clear_soft_references); 1567} 1568 1569HomogeneousSpaceCompactResult Heap::PerformHomogeneousSpaceCompact() { 1570 Thread* self = Thread::Current(); 1571 // Inc requested homogeneous space compaction. 1572 count_requested_homogeneous_space_compaction_++; 1573 // Store performed homogeneous space compaction at a new request arrival. 1574 ThreadList* tl = Runtime::Current()->GetThreadList(); 1575 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1576 Locks::mutator_lock_->AssertNotHeld(self); 1577 { 1578 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1579 MutexLock mu(self, *gc_complete_lock_); 1580 // Ensure there is only one GC at a time. 1581 WaitForGcToCompleteLocked(kGcCauseHomogeneousSpaceCompact, self); 1582 // Homogeneous space compaction is a copying transition, can't run it if the moving GC disable count 1583 // is non zero. 1584 // If the collector type changed to something which doesn't benefit from homogeneous space compaction, 1585 // exit. 1586 if (disable_moving_gc_count_ != 0 || IsMovingGc(collector_type_) || 1587 !main_space_->CanMoveObjects()) { 1588 return HomogeneousSpaceCompactResult::kErrorReject; 1589 } 1590 collector_type_running_ = kCollectorTypeHomogeneousSpaceCompact; 1591 } 1592 if (Runtime::Current()->IsShuttingDown(self)) { 1593 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1594 // cause objects to get finalized. 1595 FinishGC(self, collector::kGcTypeNone); 1596 return HomogeneousSpaceCompactResult::kErrorVMShuttingDown; 1597 } 1598 // Suspend all threads. 1599 tl->SuspendAll(); 1600 uint64_t start_time = NanoTime(); 1601 // Launch compaction. 1602 space::MallocSpace* to_space = main_space_backup_.release(); 1603 space::MallocSpace* from_space = main_space_; 1604 to_space->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1605 const uint64_t space_size_before_compaction = from_space->Size(); 1606 AddSpace(to_space); 1607 // Make sure that we will have enough room to copy. 1608 CHECK_GE(to_space->GetFootprintLimit(), from_space->GetFootprintLimit()); 1609 Compact(to_space, from_space, kGcCauseHomogeneousSpaceCompact); 1610 const uint64_t space_size_after_compaction = to_space->Size(); 1611 main_space_ = to_space; 1612 main_space_backup_.reset(from_space); 1613 RemoveSpace(from_space); 1614 SetSpaceAsDefault(main_space_); // Set as default to reset the proper dlmalloc space. 1615 // Update performed homogeneous space compaction count. 1616 count_performed_homogeneous_space_compaction_++; 1617 // Print statics log and resume all threads. 1618 uint64_t duration = NanoTime() - start_time; 1619 VLOG(heap) << "Heap homogeneous space compaction took " << PrettyDuration(duration) << " size: " 1620 << PrettySize(space_size_before_compaction) << " -> " 1621 << PrettySize(space_size_after_compaction) << " compact-ratio: " 1622 << std::fixed << static_cast<double>(space_size_after_compaction) / 1623 static_cast<double>(space_size_before_compaction); 1624 tl->ResumeAll(); 1625 // Finish GC. 1626 reference_processor_.EnqueueClearedReferences(self); 1627 GrowForUtilization(semi_space_collector_); 1628 FinishGC(self, collector::kGcTypeFull); 1629 return HomogeneousSpaceCompactResult::kSuccess; 1630} 1631 1632void Heap::TransitionCollector(CollectorType collector_type) { 1633 if (collector_type == collector_type_) { 1634 return; 1635 } 1636 VLOG(heap) << "TransitionCollector: " << static_cast<int>(collector_type_) 1637 << " -> " << static_cast<int>(collector_type); 1638 uint64_t start_time = NanoTime(); 1639 uint32_t before_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1640 Runtime* const runtime = Runtime::Current(); 1641 ThreadList* const tl = runtime->GetThreadList(); 1642 Thread* const self = Thread::Current(); 1643 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 1644 Locks::mutator_lock_->AssertNotHeld(self); 1645 // Busy wait until we can GC (StartGC can fail if we have a non-zero 1646 // compacting_gc_disable_count_, this should rarely occurs). 1647 for (;;) { 1648 { 1649 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 1650 MutexLock mu(self, *gc_complete_lock_); 1651 // Ensure there is only one GC at a time. 1652 WaitForGcToCompleteLocked(kGcCauseCollectorTransition, self); 1653 // Currently we only need a heap transition if we switch from a moving collector to a 1654 // non-moving one, or visa versa. 1655 const bool copying_transition = IsMovingGc(collector_type_) != IsMovingGc(collector_type); 1656 // If someone else beat us to it and changed the collector before we could, exit. 1657 // This is safe to do before the suspend all since we set the collector_type_running_ before 1658 // we exit the loop. If another thread attempts to do the heap transition before we exit, 1659 // then it would get blocked on WaitForGcToCompleteLocked. 1660 if (collector_type == collector_type_) { 1661 return; 1662 } 1663 // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. 1664 if (!copying_transition || disable_moving_gc_count_ == 0) { 1665 // TODO: Not hard code in semi-space collector? 1666 collector_type_running_ = copying_transition ? kCollectorTypeSS : collector_type; 1667 break; 1668 } 1669 } 1670 usleep(1000); 1671 } 1672 if (runtime->IsShuttingDown(self)) { 1673 // Don't allow heap transitions to happen if the runtime is shutting down since these can 1674 // cause objects to get finalized. 1675 FinishGC(self, collector::kGcTypeNone); 1676 return; 1677 } 1678 tl->SuspendAll(); 1679 switch (collector_type) { 1680 case kCollectorTypeSS: { 1681 if (!IsMovingGc(collector_type_)) { 1682 // Create the bump pointer space from the backup space. 1683 CHECK(main_space_backup_ != nullptr); 1684 std::unique_ptr<MemMap> mem_map(main_space_backup_->ReleaseMemMap()); 1685 // We are transitioning from non moving GC -> moving GC, since we copied from the bump 1686 // pointer space last transition it will be protected. 1687 CHECK(mem_map != nullptr); 1688 mem_map->Protect(PROT_READ | PROT_WRITE); 1689 bump_pointer_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space", 1690 mem_map.release()); 1691 AddSpace(bump_pointer_space_); 1692 Compact(bump_pointer_space_, main_space_, kGcCauseCollectorTransition); 1693 // Use the now empty main space mem map for the bump pointer temp space. 1694 mem_map.reset(main_space_->ReleaseMemMap()); 1695 // Unset the pointers just in case. 1696 if (dlmalloc_space_ == main_space_) { 1697 dlmalloc_space_ = nullptr; 1698 } else if (rosalloc_space_ == main_space_) { 1699 rosalloc_space_ = nullptr; 1700 } 1701 // Remove the main space so that we don't try to trim it, this doens't work for debug 1702 // builds since RosAlloc attempts to read the magic number from a protected page. 1703 RemoveSpace(main_space_); 1704 RemoveRememberedSet(main_space_); 1705 delete main_space_; // Delete the space since it has been removed. 1706 main_space_ = nullptr; 1707 RemoveRememberedSet(main_space_backup_.get()); 1708 main_space_backup_.reset(nullptr); // Deletes the space. 1709 temp_space_ = space::BumpPointerSpace::CreateFromMemMap("Bump pointer space 2", 1710 mem_map.release()); 1711 AddSpace(temp_space_); 1712 } 1713 break; 1714 } 1715 case kCollectorTypeMS: 1716 // Fall through. 1717 case kCollectorTypeCMS: { 1718 if (IsMovingGc(collector_type_)) { 1719 CHECK(temp_space_ != nullptr); 1720 std::unique_ptr<MemMap> mem_map(temp_space_->ReleaseMemMap()); 1721 RemoveSpace(temp_space_); 1722 temp_space_ = nullptr; 1723 mem_map->Protect(PROT_READ | PROT_WRITE); 1724 CreateMainMallocSpace(mem_map.get(), kDefaultInitialSize, 1725 std::min(mem_map->Size(), growth_limit_), mem_map->Size()); 1726 mem_map.release(); 1727 // Compact to the main space from the bump pointer space, don't need to swap semispaces. 1728 AddSpace(main_space_); 1729 Compact(main_space_, bump_pointer_space_, kGcCauseCollectorTransition); 1730 mem_map.reset(bump_pointer_space_->ReleaseMemMap()); 1731 RemoveSpace(bump_pointer_space_); 1732 bump_pointer_space_ = nullptr; 1733 const char* name = kUseRosAlloc ? kRosAllocSpaceName[1] : kDlMallocSpaceName[1]; 1734 // Temporarily unprotect the backup mem map so rosalloc can write the debug magic number. 1735 if (kIsDebugBuild && kUseRosAlloc) { 1736 mem_map->Protect(PROT_READ | PROT_WRITE); 1737 } 1738 main_space_backup_.reset(CreateMallocSpaceFromMemMap( 1739 mem_map.get(), kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1740 mem_map->Size(), name, true)); 1741 if (kIsDebugBuild && kUseRosAlloc) { 1742 mem_map->Protect(PROT_NONE); 1743 } 1744 mem_map.release(); 1745 } 1746 break; 1747 } 1748 default: { 1749 LOG(FATAL) << "Attempted to transition to invalid collector type " 1750 << static_cast<size_t>(collector_type); 1751 break; 1752 } 1753 } 1754 ChangeCollector(collector_type); 1755 tl->ResumeAll(); 1756 // Can't call into java code with all threads suspended. 1757 reference_processor_.EnqueueClearedReferences(self); 1758 uint64_t duration = NanoTime() - start_time; 1759 GrowForUtilization(semi_space_collector_); 1760 FinishGC(self, collector::kGcTypeFull); 1761 int32_t after_allocated = num_bytes_allocated_.LoadSequentiallyConsistent(); 1762 int32_t delta_allocated = before_allocated - after_allocated; 1763 std::string saved_str; 1764 if (delta_allocated >= 0) { 1765 saved_str = " saved at least " + PrettySize(delta_allocated); 1766 } else { 1767 saved_str = " expanded " + PrettySize(-delta_allocated); 1768 } 1769 VLOG(heap) << "Heap transition to " << process_state_ << " took " 1770 << PrettyDuration(duration) << saved_str; 1771} 1772 1773void Heap::ChangeCollector(CollectorType collector_type) { 1774 // TODO: Only do this with all mutators suspended to avoid races. 1775 if (collector_type != collector_type_) { 1776 if (collector_type == kCollectorTypeMC) { 1777 // Don't allow mark compact unless support is compiled in. 1778 CHECK(kMarkCompactSupport); 1779 } 1780 collector_type_ = collector_type; 1781 gc_plan_.clear(); 1782 switch (collector_type_) { 1783 case kCollectorTypeCC: // Fall-through. 1784 case kCollectorTypeMC: // Fall-through. 1785 case kCollectorTypeSS: // Fall-through. 1786 case kCollectorTypeGSS: { 1787 gc_plan_.push_back(collector::kGcTypeFull); 1788 if (use_tlab_) { 1789 ChangeAllocator(kAllocatorTypeTLAB); 1790 } else { 1791 ChangeAllocator(kAllocatorTypeBumpPointer); 1792 } 1793 break; 1794 } 1795 case kCollectorTypeMS: { 1796 gc_plan_.push_back(collector::kGcTypeSticky); 1797 gc_plan_.push_back(collector::kGcTypePartial); 1798 gc_plan_.push_back(collector::kGcTypeFull); 1799 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1800 break; 1801 } 1802 case kCollectorTypeCMS: { 1803 gc_plan_.push_back(collector::kGcTypeSticky); 1804 gc_plan_.push_back(collector::kGcTypePartial); 1805 gc_plan_.push_back(collector::kGcTypeFull); 1806 ChangeAllocator(kUseRosAlloc ? kAllocatorTypeRosAlloc : kAllocatorTypeDlMalloc); 1807 break; 1808 } 1809 default: { 1810 UNIMPLEMENTED(FATAL); 1811 UNREACHABLE(); 1812 } 1813 } 1814 if (IsGcConcurrent()) { 1815 concurrent_start_bytes_ = 1816 std::max(max_allowed_footprint_, kMinConcurrentRemainingBytes) - kMinConcurrentRemainingBytes; 1817 } else { 1818 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 1819 } 1820 } 1821} 1822 1823// Special compacting collector which uses sub-optimal bin packing to reduce zygote space size. 1824class ZygoteCompactingCollector FINAL : public collector::SemiSpace { 1825 public: 1826 explicit ZygoteCompactingCollector(gc::Heap* heap) : SemiSpace(heap, false, "zygote collector"), 1827 bin_live_bitmap_(nullptr), bin_mark_bitmap_(nullptr) { 1828 } 1829 1830 void BuildBins(space::ContinuousSpace* space) { 1831 bin_live_bitmap_ = space->GetLiveBitmap(); 1832 bin_mark_bitmap_ = space->GetMarkBitmap(); 1833 BinContext context; 1834 context.prev_ = reinterpret_cast<uintptr_t>(space->Begin()); 1835 context.collector_ = this; 1836 WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 1837 // Note: This requires traversing the space in increasing order of object addresses. 1838 bin_live_bitmap_->Walk(Callback, reinterpret_cast<void*>(&context)); 1839 // Add the last bin which spans after the last object to the end of the space. 1840 AddBin(reinterpret_cast<uintptr_t>(space->End()) - context.prev_, context.prev_); 1841 } 1842 1843 private: 1844 struct BinContext { 1845 uintptr_t prev_; // The end of the previous object. 1846 ZygoteCompactingCollector* collector_; 1847 }; 1848 // Maps from bin sizes to locations. 1849 std::multimap<size_t, uintptr_t> bins_; 1850 // Live bitmap of the space which contains the bins. 1851 accounting::ContinuousSpaceBitmap* bin_live_bitmap_; 1852 // Mark bitmap of the space which contains the bins. 1853 accounting::ContinuousSpaceBitmap* bin_mark_bitmap_; 1854 1855 static void Callback(mirror::Object* obj, void* arg) 1856 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 1857 DCHECK(arg != nullptr); 1858 BinContext* context = reinterpret_cast<BinContext*>(arg); 1859 ZygoteCompactingCollector* collector = context->collector_; 1860 uintptr_t object_addr = reinterpret_cast<uintptr_t>(obj); 1861 size_t bin_size = object_addr - context->prev_; 1862 // Add the bin consisting of the end of the previous object to the start of the current object. 1863 collector->AddBin(bin_size, context->prev_); 1864 context->prev_ = object_addr + RoundUp(obj->SizeOf(), kObjectAlignment); 1865 } 1866 1867 void AddBin(size_t size, uintptr_t position) { 1868 if (size != 0) { 1869 bins_.insert(std::make_pair(size, position)); 1870 } 1871 } 1872 1873 virtual bool ShouldSweepSpace(space::ContinuousSpace* space) const { 1874 // Don't sweep any spaces since we probably blasted the internal accounting of the free list 1875 // allocator. 1876 UNUSED(space); 1877 return false; 1878 } 1879 1880 virtual mirror::Object* MarkNonForwardedObject(mirror::Object* obj) 1881 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_, Locks::mutator_lock_) { 1882 size_t object_size = RoundUp(obj->SizeOf(), kObjectAlignment); 1883 mirror::Object* forward_address; 1884 // Find the smallest bin which we can move obj in. 1885 auto it = bins_.lower_bound(object_size); 1886 if (it == bins_.end()) { 1887 // No available space in the bins, place it in the target space instead (grows the zygote 1888 // space). 1889 size_t bytes_allocated; 1890 forward_address = to_space_->Alloc(self_, object_size, &bytes_allocated, nullptr); 1891 if (to_space_live_bitmap_ != nullptr) { 1892 to_space_live_bitmap_->Set(forward_address); 1893 } else { 1894 GetHeap()->GetNonMovingSpace()->GetLiveBitmap()->Set(forward_address); 1895 GetHeap()->GetNonMovingSpace()->GetMarkBitmap()->Set(forward_address); 1896 } 1897 } else { 1898 size_t size = it->first; 1899 uintptr_t pos = it->second; 1900 bins_.erase(it); // Erase the old bin which we replace with the new smaller bin. 1901 forward_address = reinterpret_cast<mirror::Object*>(pos); 1902 // Set the live and mark bits so that sweeping system weaks works properly. 1903 bin_live_bitmap_->Set(forward_address); 1904 bin_mark_bitmap_->Set(forward_address); 1905 DCHECK_GE(size, object_size); 1906 AddBin(size - object_size, pos + object_size); // Add a new bin with the remaining space. 1907 } 1908 // Copy the object over to its new location. 1909 memcpy(reinterpret_cast<void*>(forward_address), obj, object_size); 1910 if (kUseBakerOrBrooksReadBarrier) { 1911 obj->AssertReadBarrierPointer(); 1912 if (kUseBrooksReadBarrier) { 1913 DCHECK_EQ(forward_address->GetReadBarrierPointer(), obj); 1914 forward_address->SetReadBarrierPointer(forward_address); 1915 } 1916 forward_address->AssertReadBarrierPointer(); 1917 } 1918 return forward_address; 1919 } 1920}; 1921 1922void Heap::UnBindBitmaps() { 1923 TimingLogger::ScopedTiming t("UnBindBitmaps", GetCurrentGcIteration()->GetTimings()); 1924 for (const auto& space : GetContinuousSpaces()) { 1925 if (space->IsContinuousMemMapAllocSpace()) { 1926 space::ContinuousMemMapAllocSpace* alloc_space = space->AsContinuousMemMapAllocSpace(); 1927 if (alloc_space->HasBoundBitmaps()) { 1928 alloc_space->UnBindBitmaps(); 1929 } 1930 } 1931 } 1932} 1933 1934void Heap::PreZygoteFork() { 1935 CollectGarbageInternal(collector::kGcTypeFull, kGcCauseBackground, false); 1936 Thread* self = Thread::Current(); 1937 MutexLock mu(self, zygote_creation_lock_); 1938 // Try to see if we have any Zygote spaces. 1939 if (HasZygoteSpace()) { 1940 LOG(WARNING) << __FUNCTION__ << " called when we already have a zygote space."; 1941 return; 1942 } 1943 Runtime::Current()->GetInternTable()->SwapPostZygoteWithPreZygote(); 1944 Runtime::Current()->GetClassLinker()->MoveClassTableToPreZygote(); 1945 VLOG(heap) << "Starting PreZygoteFork"; 1946 // Trim the pages at the end of the non moving space. 1947 non_moving_space_->Trim(); 1948 // The end of the non-moving space may be protected, unprotect it so that we can copy the zygote 1949 // there. 1950 non_moving_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1951 const bool same_space = non_moving_space_ == main_space_; 1952 if (kCompactZygote) { 1953 // Can't compact if the non moving space is the same as the main space. 1954 DCHECK(semi_space_collector_ != nullptr); 1955 // Temporarily disable rosalloc verification because the zygote 1956 // compaction will mess up the rosalloc internal metadata. 1957 ScopedDisableRosAllocVerification disable_rosalloc_verif(this); 1958 ZygoteCompactingCollector zygote_collector(this); 1959 zygote_collector.BuildBins(non_moving_space_); 1960 // Create a new bump pointer space which we will compact into. 1961 space::BumpPointerSpace target_space("zygote bump space", non_moving_space_->End(), 1962 non_moving_space_->Limit()); 1963 // Compact the bump pointer space to a new zygote bump pointer space. 1964 bool reset_main_space = false; 1965 if (IsMovingGc(collector_type_)) { 1966 zygote_collector.SetFromSpace(bump_pointer_space_); 1967 } else { 1968 CHECK(main_space_ != nullptr); 1969 // Copy from the main space. 1970 zygote_collector.SetFromSpace(main_space_); 1971 reset_main_space = true; 1972 } 1973 zygote_collector.SetToSpace(&target_space); 1974 zygote_collector.SetSwapSemiSpaces(false); 1975 zygote_collector.Run(kGcCauseCollectorTransition, false); 1976 if (reset_main_space) { 1977 main_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1978 madvise(main_space_->Begin(), main_space_->Capacity(), MADV_DONTNEED); 1979 MemMap* mem_map = main_space_->ReleaseMemMap(); 1980 RemoveSpace(main_space_); 1981 space::Space* old_main_space = main_space_; 1982 CreateMainMallocSpace(mem_map, kDefaultInitialSize, std::min(mem_map->Size(), growth_limit_), 1983 mem_map->Size()); 1984 delete old_main_space; 1985 AddSpace(main_space_); 1986 } else { 1987 bump_pointer_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 1988 } 1989 if (temp_space_ != nullptr) { 1990 CHECK(temp_space_->IsEmpty()); 1991 } 1992 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 1993 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 1994 // Update the end and write out image. 1995 non_moving_space_->SetEnd(target_space.End()); 1996 non_moving_space_->SetLimit(target_space.Limit()); 1997 VLOG(heap) << "Zygote space size " << non_moving_space_->Size() << " bytes"; 1998 } 1999 // Change the collector to the post zygote one. 2000 ChangeCollector(foreground_collector_type_); 2001 // Save the old space so that we can remove it after we complete creating the zygote space. 2002 space::MallocSpace* old_alloc_space = non_moving_space_; 2003 // Turn the current alloc space into a zygote space and obtain the new alloc space composed of 2004 // the remaining available space. 2005 // Remove the old space before creating the zygote space since creating the zygote space sets 2006 // the old alloc space's bitmaps to nullptr. 2007 RemoveSpace(old_alloc_space); 2008 if (collector::SemiSpace::kUseRememberedSet) { 2009 // Sanity bound check. 2010 FindRememberedSetFromSpace(old_alloc_space)->AssertAllDirtyCardsAreWithinSpace(); 2011 // Remove the remembered set for the now zygote space (the old 2012 // non-moving space). Note now that we have compacted objects into 2013 // the zygote space, the data in the remembered set is no longer 2014 // needed. The zygote space will instead have a mod-union table 2015 // from this point on. 2016 RemoveRememberedSet(old_alloc_space); 2017 } 2018 // Remaining space becomes the new non moving space. 2019 zygote_space_ = old_alloc_space->CreateZygoteSpace(kNonMovingSpaceName, low_memory_mode_, 2020 &non_moving_space_); 2021 CHECK(!non_moving_space_->CanMoveObjects()); 2022 if (same_space) { 2023 main_space_ = non_moving_space_; 2024 SetSpaceAsDefault(main_space_); 2025 } 2026 delete old_alloc_space; 2027 CHECK(HasZygoteSpace()) << "Failed creating zygote space"; 2028 AddSpace(zygote_space_); 2029 non_moving_space_->SetFootprintLimit(non_moving_space_->Capacity()); 2030 AddSpace(non_moving_space_); 2031 // Create the zygote space mod union table. 2032 accounting::ModUnionTable* mod_union_table = 2033 new accounting::ModUnionTableCardCache("zygote space mod-union table", this, 2034 zygote_space_); 2035 CHECK(mod_union_table != nullptr) << "Failed to create zygote space mod-union table"; 2036 // Set all the cards in the mod-union table since we don't know which objects contain references 2037 // to large objects. 2038 mod_union_table->SetCards(); 2039 AddModUnionTable(mod_union_table); 2040 if (collector::SemiSpace::kUseRememberedSet) { 2041 // Add a new remembered set for the post-zygote non-moving space. 2042 accounting::RememberedSet* post_zygote_non_moving_space_rem_set = 2043 new accounting::RememberedSet("Post-zygote non-moving space remembered set", this, 2044 non_moving_space_); 2045 CHECK(post_zygote_non_moving_space_rem_set != nullptr) 2046 << "Failed to create post-zygote non-moving space remembered set"; 2047 AddRememberedSet(post_zygote_non_moving_space_rem_set); 2048 } 2049} 2050 2051void Heap::FlushAllocStack() { 2052 MarkAllocStackAsLive(allocation_stack_.get()); 2053 allocation_stack_->Reset(); 2054} 2055 2056void Heap::MarkAllocStack(accounting::ContinuousSpaceBitmap* bitmap1, 2057 accounting::ContinuousSpaceBitmap* bitmap2, 2058 accounting::LargeObjectBitmap* large_objects, 2059 accounting::ObjectStack* stack) { 2060 DCHECK(bitmap1 != nullptr); 2061 DCHECK(bitmap2 != nullptr); 2062 mirror::Object** limit = stack->End(); 2063 for (mirror::Object** it = stack->Begin(); it != limit; ++it) { 2064 const mirror::Object* obj = *it; 2065 if (!kUseThreadLocalAllocationStack || obj != nullptr) { 2066 if (bitmap1->HasAddress(obj)) { 2067 bitmap1->Set(obj); 2068 } else if (bitmap2->HasAddress(obj)) { 2069 bitmap2->Set(obj); 2070 } else { 2071 DCHECK(large_objects != nullptr); 2072 large_objects->Set(obj); 2073 } 2074 } 2075 } 2076} 2077 2078void Heap::SwapSemiSpaces() { 2079 CHECK(bump_pointer_space_ != nullptr); 2080 CHECK(temp_space_ != nullptr); 2081 std::swap(bump_pointer_space_, temp_space_); 2082} 2083 2084void Heap::Compact(space::ContinuousMemMapAllocSpace* target_space, 2085 space::ContinuousMemMapAllocSpace* source_space, 2086 GcCause gc_cause) { 2087 CHECK(kMovingCollector); 2088 if (target_space != source_space) { 2089 // Don't swap spaces since this isn't a typical semi space collection. 2090 semi_space_collector_->SetSwapSemiSpaces(false); 2091 semi_space_collector_->SetFromSpace(source_space); 2092 semi_space_collector_->SetToSpace(target_space); 2093 semi_space_collector_->Run(gc_cause, false); 2094 } else { 2095 CHECK(target_space->IsBumpPointerSpace()) 2096 << "In-place compaction is only supported for bump pointer spaces"; 2097 mark_compact_collector_->SetSpace(target_space->AsBumpPointerSpace()); 2098 mark_compact_collector_->Run(kGcCauseCollectorTransition, false); 2099 } 2100} 2101 2102collector::GcType Heap::CollectGarbageInternal(collector::GcType gc_type, GcCause gc_cause, 2103 bool clear_soft_references) { 2104 Thread* self = Thread::Current(); 2105 Runtime* runtime = Runtime::Current(); 2106 // If the heap can't run the GC, silently fail and return that no GC was run. 2107 switch (gc_type) { 2108 case collector::kGcTypePartial: { 2109 if (!HasZygoteSpace()) { 2110 return collector::kGcTypeNone; 2111 } 2112 break; 2113 } 2114 default: { 2115 // Other GC types don't have any special cases which makes them not runnable. The main case 2116 // here is full GC. 2117 } 2118 } 2119 ScopedThreadStateChange tsc(self, kWaitingPerformingGc); 2120 Locks::mutator_lock_->AssertNotHeld(self); 2121 if (self->IsHandlingStackOverflow()) { 2122 // If we are throwing a stack overflow error we probably don't have enough remaining stack 2123 // space to run the GC. 2124 return collector::kGcTypeNone; 2125 } 2126 bool compacting_gc; 2127 { 2128 gc_complete_lock_->AssertNotHeld(self); 2129 ScopedThreadStateChange tsc2(self, kWaitingForGcToComplete); 2130 MutexLock mu(self, *gc_complete_lock_); 2131 // Ensure there is only one GC at a time. 2132 WaitForGcToCompleteLocked(gc_cause, self); 2133 compacting_gc = IsMovingGc(collector_type_); 2134 // GC can be disabled if someone has a used GetPrimitiveArrayCritical. 2135 if (compacting_gc && disable_moving_gc_count_ != 0) { 2136 LOG(WARNING) << "Skipping GC due to disable moving GC count " << disable_moving_gc_count_; 2137 return collector::kGcTypeNone; 2138 } 2139 collector_type_running_ = collector_type_; 2140 } 2141 2142 if (gc_cause == kGcCauseForAlloc && runtime->HasStatsEnabled()) { 2143 ++runtime->GetStats()->gc_for_alloc_count; 2144 ++self->GetStats()->gc_for_alloc_count; 2145 } 2146 const uint64_t bytes_allocated_before_gc = GetBytesAllocated(); 2147 // Approximate heap size. 2148 ATRACE_INT("Heap size (KB)", bytes_allocated_before_gc / KB); 2149 2150 DCHECK_LT(gc_type, collector::kGcTypeMax); 2151 DCHECK_NE(gc_type, collector::kGcTypeNone); 2152 2153 collector::GarbageCollector* collector = nullptr; 2154 // TODO: Clean this up. 2155 if (compacting_gc) { 2156 DCHECK(current_allocator_ == kAllocatorTypeBumpPointer || 2157 current_allocator_ == kAllocatorTypeTLAB); 2158 switch (collector_type_) { 2159 case kCollectorTypeSS: 2160 // Fall-through. 2161 case kCollectorTypeGSS: 2162 semi_space_collector_->SetFromSpace(bump_pointer_space_); 2163 semi_space_collector_->SetToSpace(temp_space_); 2164 semi_space_collector_->SetSwapSemiSpaces(true); 2165 collector = semi_space_collector_; 2166 break; 2167 case kCollectorTypeCC: 2168 collector = concurrent_copying_collector_; 2169 break; 2170 case kCollectorTypeMC: 2171 mark_compact_collector_->SetSpace(bump_pointer_space_); 2172 collector = mark_compact_collector_; 2173 break; 2174 default: 2175 LOG(FATAL) << "Invalid collector type " << static_cast<size_t>(collector_type_); 2176 } 2177 if (collector != mark_compact_collector_) { 2178 temp_space_->GetMemMap()->Protect(PROT_READ | PROT_WRITE); 2179 CHECK(temp_space_->IsEmpty()); 2180 } 2181 gc_type = collector::kGcTypeFull; // TODO: Not hard code this in. 2182 } else if (current_allocator_ == kAllocatorTypeRosAlloc || 2183 current_allocator_ == kAllocatorTypeDlMalloc) { 2184 collector = FindCollectorByGcType(gc_type); 2185 } else { 2186 LOG(FATAL) << "Invalid current allocator " << current_allocator_; 2187 } 2188 if (IsGcConcurrent()) { 2189 // Disable concurrent GC check so that we don't have spammy JNI requests. 2190 // This gets recalculated in GrowForUtilization. It is important that it is disabled / 2191 // calculated in the same thread so that there aren't any races that can cause it to become 2192 // permanantly disabled. b/17942071 2193 concurrent_start_bytes_ = std::numeric_limits<size_t>::max(); 2194 } 2195 CHECK(collector != nullptr) 2196 << "Could not find garbage collector with collector_type=" 2197 << static_cast<size_t>(collector_type_) << " and gc_type=" << gc_type; 2198 collector->Run(gc_cause, clear_soft_references || runtime->IsZygote()); 2199 total_objects_freed_ever_ += GetCurrentGcIteration()->GetFreedObjects(); 2200 total_bytes_freed_ever_ += GetCurrentGcIteration()->GetFreedBytes(); 2201 RequestTrim(self); 2202 // Enqueue cleared references. 2203 reference_processor_.EnqueueClearedReferences(self); 2204 // Grow the heap so that we know when to perform the next GC. 2205 GrowForUtilization(collector, bytes_allocated_before_gc); 2206 const size_t duration = GetCurrentGcIteration()->GetDurationNs(); 2207 const std::vector<uint64_t>& pause_times = GetCurrentGcIteration()->GetPauseTimes(); 2208 // Print the GC if it is an explicit GC (e.g. Runtime.gc()) or a slow GC 2209 // (mutator time blocked >= long_pause_log_threshold_). 2210 bool log_gc = gc_cause == kGcCauseExplicit; 2211 if (!log_gc && CareAboutPauseTimes()) { 2212 // GC for alloc pauses the allocating thread, so consider it as a pause. 2213 log_gc = duration > long_gc_log_threshold_ || 2214 (gc_cause == kGcCauseForAlloc && duration > long_pause_log_threshold_); 2215 for (uint64_t pause : pause_times) { 2216 log_gc = log_gc || pause >= long_pause_log_threshold_; 2217 } 2218 } 2219 if (log_gc) { 2220 const size_t percent_free = GetPercentFree(); 2221 const size_t current_heap_size = GetBytesAllocated(); 2222 const size_t total_memory = GetTotalMemory(); 2223 std::ostringstream pause_string; 2224 for (size_t i = 0; i < pause_times.size(); ++i) { 2225 pause_string << PrettyDuration((pause_times[i] / 1000) * 1000) 2226 << ((i != pause_times.size() - 1) ? "," : ""); 2227 } 2228 LOG(INFO) << gc_cause << " " << collector->GetName() 2229 << " GC freed " << current_gc_iteration_.GetFreedObjects() << "(" 2230 << PrettySize(current_gc_iteration_.GetFreedBytes()) << ") AllocSpace objects, " 2231 << current_gc_iteration_.GetFreedLargeObjects() << "(" 2232 << PrettySize(current_gc_iteration_.GetFreedLargeObjectBytes()) << ") LOS objects, " 2233 << percent_free << "% free, " << PrettySize(current_heap_size) << "/" 2234 << PrettySize(total_memory) << ", " << "paused " << pause_string.str() 2235 << " total " << PrettyDuration((duration / 1000) * 1000); 2236 VLOG(heap) << Dumpable<TimingLogger>(*current_gc_iteration_.GetTimings()); 2237 } 2238 FinishGC(self, gc_type); 2239 // Inform DDMS that a GC completed. 2240 Dbg::GcDidFinish(); 2241 return gc_type; 2242} 2243 2244void Heap::FinishGC(Thread* self, collector::GcType gc_type) { 2245 MutexLock mu(self, *gc_complete_lock_); 2246 collector_type_running_ = kCollectorTypeNone; 2247 if (gc_type != collector::kGcTypeNone) { 2248 last_gc_type_ = gc_type; 2249 } 2250 // Wake anyone who may have been waiting for the GC to complete. 2251 gc_complete_cond_->Broadcast(self); 2252} 2253 2254static void RootMatchesObjectVisitor(mirror::Object** root, void* arg, 2255 const RootInfo& /*root_info*/) { 2256 mirror::Object* obj = reinterpret_cast<mirror::Object*>(arg); 2257 if (*root == obj) { 2258 LOG(INFO) << "Object " << obj << " is a root"; 2259 } 2260} 2261 2262class ScanVisitor { 2263 public: 2264 void operator()(const mirror::Object* obj) const { 2265 LOG(ERROR) << "Would have rescanned object " << obj; 2266 } 2267}; 2268 2269// Verify a reference from an object. 2270class VerifyReferenceVisitor { 2271 public: 2272 explicit VerifyReferenceVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2273 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) 2274 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) {} 2275 2276 size_t GetFailureCount() const { 2277 return fail_count_->LoadSequentiallyConsistent(); 2278 } 2279 2280 void operator()(mirror::Class* klass, mirror::Reference* ref) const 2281 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2282 UNUSED(klass); 2283 if (verify_referent_) { 2284 VerifyReference(ref, ref->GetReferent(), mirror::Reference::ReferentOffset()); 2285 } 2286 } 2287 2288 void operator()(mirror::Object* obj, MemberOffset offset, bool /*is_static*/) const 2289 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2290 VerifyReference(obj, obj->GetFieldObject<mirror::Object>(offset), offset); 2291 } 2292 2293 bool IsLive(mirror::Object* obj) const NO_THREAD_SAFETY_ANALYSIS { 2294 return heap_->IsLiveObjectLocked(obj, true, false, true); 2295 } 2296 2297 static void VerifyRootCallback(mirror::Object** root, void* arg, const RootInfo& root_info) 2298 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 2299 VerifyReferenceVisitor* visitor = reinterpret_cast<VerifyReferenceVisitor*>(arg); 2300 if (!visitor->VerifyReference(nullptr, *root, MemberOffset(0))) { 2301 LOG(ERROR) << "Root " << *root << " is dead with type " << PrettyTypeOf(*root) 2302 << " thread_id= " << root_info.GetThreadId() << " root_type= " << root_info.GetType(); 2303 } 2304 } 2305 2306 private: 2307 // TODO: Fix the no thread safety analysis. 2308 // Returns false on failure. 2309 bool VerifyReference(mirror::Object* obj, mirror::Object* ref, MemberOffset offset) const 2310 NO_THREAD_SAFETY_ANALYSIS { 2311 if (ref == nullptr || IsLive(ref)) { 2312 // Verify that the reference is live. 2313 return true; 2314 } 2315 if (fail_count_->FetchAndAddSequentiallyConsistent(1) == 0) { 2316 // Print message on only on first failure to prevent spam. 2317 LOG(ERROR) << "!!!!!!!!!!!!!!Heap corruption detected!!!!!!!!!!!!!!!!!!!"; 2318 } 2319 if (obj != nullptr) { 2320 // Only do this part for non roots. 2321 accounting::CardTable* card_table = heap_->GetCardTable(); 2322 accounting::ObjectStack* alloc_stack = heap_->allocation_stack_.get(); 2323 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2324 uint8_t* card_addr = card_table->CardFromAddr(obj); 2325 LOG(ERROR) << "Object " << obj << " references dead object " << ref << " at offset " 2326 << offset << "\n card value = " << static_cast<int>(*card_addr); 2327 if (heap_->IsValidObjectAddress(obj->GetClass())) { 2328 LOG(ERROR) << "Obj type " << PrettyTypeOf(obj); 2329 } else { 2330 LOG(ERROR) << "Object " << obj << " class(" << obj->GetClass() << ") not a heap address"; 2331 } 2332 2333 // Attempt to find the class inside of the recently freed objects. 2334 space::ContinuousSpace* ref_space = heap_->FindContinuousSpaceFromObject(ref, true); 2335 if (ref_space != nullptr && ref_space->IsMallocSpace()) { 2336 space::MallocSpace* space = ref_space->AsMallocSpace(); 2337 mirror::Class* ref_class = space->FindRecentFreedObject(ref); 2338 if (ref_class != nullptr) { 2339 LOG(ERROR) << "Reference " << ref << " found as a recently freed object with class " 2340 << PrettyClass(ref_class); 2341 } else { 2342 LOG(ERROR) << "Reference " << ref << " not found as a recently freed object"; 2343 } 2344 } 2345 2346 if (ref->GetClass() != nullptr && heap_->IsValidObjectAddress(ref->GetClass()) && 2347 ref->GetClass()->IsClass()) { 2348 LOG(ERROR) << "Ref type " << PrettyTypeOf(ref); 2349 } else { 2350 LOG(ERROR) << "Ref " << ref << " class(" << ref->GetClass() 2351 << ") is not a valid heap address"; 2352 } 2353 2354 card_table->CheckAddrIsInCardTable(reinterpret_cast<const uint8_t*>(obj)); 2355 void* cover_begin = card_table->AddrFromCard(card_addr); 2356 void* cover_end = reinterpret_cast<void*>(reinterpret_cast<size_t>(cover_begin) + 2357 accounting::CardTable::kCardSize); 2358 LOG(ERROR) << "Card " << reinterpret_cast<void*>(card_addr) << " covers " << cover_begin 2359 << "-" << cover_end; 2360 accounting::ContinuousSpaceBitmap* bitmap = 2361 heap_->GetLiveBitmap()->GetContinuousSpaceBitmap(obj); 2362 2363 if (bitmap == nullptr) { 2364 LOG(ERROR) << "Object " << obj << " has no bitmap"; 2365 if (!VerifyClassClass(obj->GetClass())) { 2366 LOG(ERROR) << "Object " << obj << " failed class verification!"; 2367 } 2368 } else { 2369 // Print out how the object is live. 2370 if (bitmap->Test(obj)) { 2371 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2372 } 2373 if (alloc_stack->Contains(const_cast<mirror::Object*>(obj))) { 2374 LOG(ERROR) << "Object " << obj << " found in allocation stack"; 2375 } 2376 if (live_stack->Contains(const_cast<mirror::Object*>(obj))) { 2377 LOG(ERROR) << "Object " << obj << " found in live stack"; 2378 } 2379 if (alloc_stack->Contains(const_cast<mirror::Object*>(ref))) { 2380 LOG(ERROR) << "Ref " << ref << " found in allocation stack"; 2381 } 2382 if (live_stack->Contains(const_cast<mirror::Object*>(ref))) { 2383 LOG(ERROR) << "Ref " << ref << " found in live stack"; 2384 } 2385 // Attempt to see if the card table missed the reference. 2386 ScanVisitor scan_visitor; 2387 uint8_t* byte_cover_begin = reinterpret_cast<uint8_t*>(card_table->AddrFromCard(card_addr)); 2388 card_table->Scan(bitmap, byte_cover_begin, 2389 byte_cover_begin + accounting::CardTable::kCardSize, scan_visitor); 2390 } 2391 2392 // Search to see if any of the roots reference our object. 2393 void* arg = const_cast<void*>(reinterpret_cast<const void*>(obj)); 2394 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2395 2396 // Search to see if any of the roots reference our reference. 2397 arg = const_cast<void*>(reinterpret_cast<const void*>(ref)); 2398 Runtime::Current()->VisitRoots(&RootMatchesObjectVisitor, arg); 2399 } 2400 return false; 2401 } 2402 2403 Heap* const heap_; 2404 Atomic<size_t>* const fail_count_; 2405 const bool verify_referent_; 2406}; 2407 2408// Verify all references within an object, for use with HeapBitmap::Visit. 2409class VerifyObjectVisitor { 2410 public: 2411 explicit VerifyObjectVisitor(Heap* heap, Atomic<size_t>* fail_count, bool verify_referent) 2412 : heap_(heap), fail_count_(fail_count), verify_referent_(verify_referent) { 2413 } 2414 2415 void operator()(mirror::Object* obj) const 2416 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2417 // Note: we are verifying the references in obj but not obj itself, this is because obj must 2418 // be live or else how did we find it in the live bitmap? 2419 VerifyReferenceVisitor visitor(heap_, fail_count_, verify_referent_); 2420 // The class doesn't count as a reference but we should verify it anyways. 2421 obj->VisitReferences<true>(visitor, visitor); 2422 } 2423 2424 static void VisitCallback(mirror::Object* obj, void* arg) 2425 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2426 VerifyObjectVisitor* visitor = reinterpret_cast<VerifyObjectVisitor*>(arg); 2427 visitor->operator()(obj); 2428 } 2429 2430 size_t GetFailureCount() const { 2431 return fail_count_->LoadSequentiallyConsistent(); 2432 } 2433 2434 private: 2435 Heap* const heap_; 2436 Atomic<size_t>* const fail_count_; 2437 const bool verify_referent_; 2438}; 2439 2440void Heap::PushOnAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2441 // Slow path, the allocation stack push back must have already failed. 2442 DCHECK(!allocation_stack_->AtomicPushBack(*obj)); 2443 do { 2444 // TODO: Add handle VerifyObject. 2445 StackHandleScope<1> hs(self); 2446 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2447 // Push our object into the reserve region of the allocaiton stack. This is only required due 2448 // to heap verification requiring that roots are live (either in the live bitmap or in the 2449 // allocation stack). 2450 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2451 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2452 } while (!allocation_stack_->AtomicPushBack(*obj)); 2453} 2454 2455void Heap::PushOnThreadLocalAllocationStackWithInternalGC(Thread* self, mirror::Object** obj) { 2456 // Slow path, the allocation stack push back must have already failed. 2457 DCHECK(!self->PushOnThreadLocalAllocationStack(*obj)); 2458 mirror::Object** start_address; 2459 mirror::Object** end_address; 2460 while (!allocation_stack_->AtomicBumpBack(kThreadLocalAllocationStackSize, &start_address, 2461 &end_address)) { 2462 // TODO: Add handle VerifyObject. 2463 StackHandleScope<1> hs(self); 2464 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 2465 // Push our object into the reserve region of the allocaiton stack. This is only required due 2466 // to heap verification requiring that roots are live (either in the live bitmap or in the 2467 // allocation stack). 2468 CHECK(allocation_stack_->AtomicPushBackIgnoreGrowthLimit(*obj)); 2469 // Push into the reserve allocation stack. 2470 CollectGarbageInternal(collector::kGcTypeSticky, kGcCauseForAlloc, false); 2471 } 2472 self->SetThreadLocalAllocationStack(start_address, end_address); 2473 // Retry on the new thread-local allocation stack. 2474 CHECK(self->PushOnThreadLocalAllocationStack(*obj)); // Must succeed. 2475} 2476 2477// Must do this with mutators suspended since we are directly accessing the allocation stacks. 2478size_t Heap::VerifyHeapReferences(bool verify_referents) { 2479 Thread* self = Thread::Current(); 2480 Locks::mutator_lock_->AssertExclusiveHeld(self); 2481 // Lets sort our allocation stacks so that we can efficiently binary search them. 2482 allocation_stack_->Sort(); 2483 live_stack_->Sort(); 2484 // Since we sorted the allocation stack content, need to revoke all 2485 // thread-local allocation stacks. 2486 RevokeAllThreadLocalAllocationStacks(self); 2487 Atomic<size_t> fail_count_(0); 2488 VerifyObjectVisitor visitor(this, &fail_count_, verify_referents); 2489 // Verify objects in the allocation stack since these will be objects which were: 2490 // 1. Allocated prior to the GC (pre GC verification). 2491 // 2. Allocated during the GC (pre sweep GC verification). 2492 // We don't want to verify the objects in the live stack since they themselves may be 2493 // pointing to dead objects if they are not reachable. 2494 VisitObjects(VerifyObjectVisitor::VisitCallback, &visitor); 2495 // Verify the roots: 2496 Runtime::Current()->VisitRoots(VerifyReferenceVisitor::VerifyRootCallback, &visitor); 2497 if (visitor.GetFailureCount() > 0) { 2498 // Dump mod-union tables. 2499 for (const auto& table_pair : mod_union_tables_) { 2500 accounting::ModUnionTable* mod_union_table = table_pair.second; 2501 mod_union_table->Dump(LOG(ERROR) << mod_union_table->GetName() << ": "); 2502 } 2503 // Dump remembered sets. 2504 for (const auto& table_pair : remembered_sets_) { 2505 accounting::RememberedSet* remembered_set = table_pair.second; 2506 remembered_set->Dump(LOG(ERROR) << remembered_set->GetName() << ": "); 2507 } 2508 DumpSpaces(LOG(ERROR)); 2509 } 2510 return visitor.GetFailureCount(); 2511} 2512 2513class VerifyReferenceCardVisitor { 2514 public: 2515 VerifyReferenceCardVisitor(Heap* heap, bool* failed) 2516 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, 2517 Locks::heap_bitmap_lock_) 2518 : heap_(heap), failed_(failed) { 2519 } 2520 2521 // TODO: Fix lock analysis to not use NO_THREAD_SAFETY_ANALYSIS, requires support for 2522 // annotalysis on visitors. 2523 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static) const 2524 NO_THREAD_SAFETY_ANALYSIS { 2525 mirror::Object* ref = obj->GetFieldObject<mirror::Object>(offset); 2526 // Filter out class references since changing an object's class does not mark the card as dirty. 2527 // Also handles large objects, since the only reference they hold is a class reference. 2528 if (ref != nullptr && !ref->IsClass()) { 2529 accounting::CardTable* card_table = heap_->GetCardTable(); 2530 // If the object is not dirty and it is referencing something in the live stack other than 2531 // class, then it must be on a dirty card. 2532 if (!card_table->AddrIsInCardTable(obj)) { 2533 LOG(ERROR) << "Object " << obj << " is not in the address range of the card table"; 2534 *failed_ = true; 2535 } else if (!card_table->IsDirty(obj)) { 2536 // TODO: Check mod-union tables. 2537 // Card should be either kCardDirty if it got re-dirtied after we aged it, or 2538 // kCardDirty - 1 if it didnt get touched since we aged it. 2539 accounting::ObjectStack* live_stack = heap_->live_stack_.get(); 2540 if (live_stack->ContainsSorted(ref)) { 2541 if (live_stack->ContainsSorted(obj)) { 2542 LOG(ERROR) << "Object " << obj << " found in live stack"; 2543 } 2544 if (heap_->GetLiveBitmap()->Test(obj)) { 2545 LOG(ERROR) << "Object " << obj << " found in live bitmap"; 2546 } 2547 LOG(ERROR) << "Object " << obj << " " << PrettyTypeOf(obj) 2548 << " references " << ref << " " << PrettyTypeOf(ref) << " in live stack"; 2549 2550 // Print which field of the object is dead. 2551 if (!obj->IsObjectArray()) { 2552 mirror::Class* klass = is_static ? obj->AsClass() : obj->GetClass(); 2553 CHECK(klass != NULL); 2554 mirror::ObjectArray<mirror::ArtField>* fields = is_static ? klass->GetSFields() 2555 : klass->GetIFields(); 2556 CHECK(fields != NULL); 2557 for (int32_t i = 0; i < fields->GetLength(); ++i) { 2558 mirror::ArtField* cur = fields->Get(i); 2559 if (cur->GetOffset().Int32Value() == offset.Int32Value()) { 2560 LOG(ERROR) << (is_static ? "Static " : "") << "field in the live stack is " 2561 << PrettyField(cur); 2562 break; 2563 } 2564 } 2565 } else { 2566 mirror::ObjectArray<mirror::Object>* object_array = 2567 obj->AsObjectArray<mirror::Object>(); 2568 for (int32_t i = 0; i < object_array->GetLength(); ++i) { 2569 if (object_array->Get(i) == ref) { 2570 LOG(ERROR) << (is_static ? "Static " : "") << "obj[" << i << "] = ref"; 2571 } 2572 } 2573 } 2574 2575 *failed_ = true; 2576 } 2577 } 2578 } 2579 } 2580 2581 private: 2582 Heap* const heap_; 2583 bool* const failed_; 2584}; 2585 2586class VerifyLiveStackReferences { 2587 public: 2588 explicit VerifyLiveStackReferences(Heap* heap) 2589 : heap_(heap), 2590 failed_(false) {} 2591 2592 void operator()(mirror::Object* obj) const 2593 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 2594 VerifyReferenceCardVisitor visitor(heap_, const_cast<bool*>(&failed_)); 2595 obj->VisitReferences<true>(visitor, VoidFunctor()); 2596 } 2597 2598 bool Failed() const { 2599 return failed_; 2600 } 2601 2602 private: 2603 Heap* const heap_; 2604 bool failed_; 2605}; 2606 2607bool Heap::VerifyMissingCardMarks() { 2608 Thread* self = Thread::Current(); 2609 Locks::mutator_lock_->AssertExclusiveHeld(self); 2610 // We need to sort the live stack since we binary search it. 2611 live_stack_->Sort(); 2612 // Since we sorted the allocation stack content, need to revoke all 2613 // thread-local allocation stacks. 2614 RevokeAllThreadLocalAllocationStacks(self); 2615 VerifyLiveStackReferences visitor(this); 2616 GetLiveBitmap()->Visit(visitor); 2617 // We can verify objects in the live stack since none of these should reference dead objects. 2618 for (mirror::Object** it = live_stack_->Begin(); it != live_stack_->End(); ++it) { 2619 if (!kUseThreadLocalAllocationStack || *it != nullptr) { 2620 visitor(*it); 2621 } 2622 } 2623 return !visitor.Failed(); 2624} 2625 2626void Heap::SwapStacks(Thread* self) { 2627 UNUSED(self); 2628 if (kUseThreadLocalAllocationStack) { 2629 live_stack_->AssertAllZero(); 2630 } 2631 allocation_stack_.swap(live_stack_); 2632} 2633 2634void Heap::RevokeAllThreadLocalAllocationStacks(Thread* self) { 2635 // This must be called only during the pause. 2636 CHECK(Locks::mutator_lock_->IsExclusiveHeld(self)); 2637 MutexLock mu(self, *Locks::runtime_shutdown_lock_); 2638 MutexLock mu2(self, *Locks::thread_list_lock_); 2639 std::list<Thread*> thread_list = Runtime::Current()->GetThreadList()->GetList(); 2640 for (Thread* t : thread_list) { 2641 t->RevokeThreadLocalAllocationStack(); 2642 } 2643} 2644 2645void Heap::AssertThreadLocalBuffersAreRevoked(Thread* thread) { 2646 if (kIsDebugBuild) { 2647 if (rosalloc_space_ != nullptr) { 2648 rosalloc_space_->AssertThreadLocalBuffersAreRevoked(thread); 2649 } 2650 if (bump_pointer_space_ != nullptr) { 2651 bump_pointer_space_->AssertThreadLocalBuffersAreRevoked(thread); 2652 } 2653 } 2654} 2655 2656void Heap::AssertAllBumpPointerSpaceThreadLocalBuffersAreRevoked() { 2657 if (kIsDebugBuild) { 2658 if (bump_pointer_space_ != nullptr) { 2659 bump_pointer_space_->AssertAllThreadLocalBuffersAreRevoked(); 2660 } 2661 } 2662} 2663 2664accounting::ModUnionTable* Heap::FindModUnionTableFromSpace(space::Space* space) { 2665 auto it = mod_union_tables_.find(space); 2666 if (it == mod_union_tables_.end()) { 2667 return nullptr; 2668 } 2669 return it->second; 2670} 2671 2672accounting::RememberedSet* Heap::FindRememberedSetFromSpace(space::Space* space) { 2673 auto it = remembered_sets_.find(space); 2674 if (it == remembered_sets_.end()) { 2675 return nullptr; 2676 } 2677 return it->second; 2678} 2679 2680void Heap::ProcessCards(TimingLogger* timings, bool use_rem_sets) { 2681 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2682 // Clear cards and keep track of cards cleared in the mod-union table. 2683 for (const auto& space : continuous_spaces_) { 2684 accounting::ModUnionTable* table = FindModUnionTableFromSpace(space); 2685 accounting::RememberedSet* rem_set = FindRememberedSetFromSpace(space); 2686 if (table != nullptr) { 2687 const char* name = space->IsZygoteSpace() ? "ZygoteModUnionClearCards" : 2688 "ImageModUnionClearCards"; 2689 TimingLogger::ScopedTiming t2(name, timings); 2690 table->ClearCards(); 2691 } else if (use_rem_sets && rem_set != nullptr) { 2692 DCHECK(collector::SemiSpace::kUseRememberedSet && collector_type_ == kCollectorTypeGSS) 2693 << static_cast<int>(collector_type_); 2694 TimingLogger::ScopedTiming t2("AllocSpaceRemSetClearCards", timings); 2695 rem_set->ClearCards(); 2696 } else if (space->GetType() != space::kSpaceTypeBumpPointerSpace) { 2697 TimingLogger::ScopedTiming t2("AllocSpaceClearCards", timings); 2698 // No mod union table for the AllocSpace. Age the cards so that the GC knows that these cards 2699 // were dirty before the GC started. 2700 // TODO: Need to use atomic for the case where aged(cleaning thread) -> dirty(other thread) 2701 // -> clean(cleaning thread). 2702 // The races are we either end up with: Aged card, unaged card. Since we have the checkpoint 2703 // roots and then we scan / update mod union tables after. We will always scan either card. 2704 // If we end up with the non aged card, we scan it it in the pause. 2705 card_table_->ModifyCardsAtomic(space->Begin(), space->End(), AgeCardVisitor(), 2706 VoidFunctor()); 2707 } 2708 } 2709} 2710 2711static void IdentityMarkHeapReferenceCallback(mirror::HeapReference<mirror::Object>*, void*) { 2712} 2713 2714void Heap::PreGcVerificationPaused(collector::GarbageCollector* gc) { 2715 Thread* const self = Thread::Current(); 2716 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2717 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2718 if (verify_pre_gc_heap_) { 2719 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyHeapReferences", timings); 2720 size_t failures = VerifyHeapReferences(); 2721 if (failures > 0) { 2722 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2723 << " failures"; 2724 } 2725 } 2726 // Check that all objects which reference things in the live stack are on dirty cards. 2727 if (verify_missing_card_marks_) { 2728 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyMissingCardMarks", timings); 2729 ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_); 2730 SwapStacks(self); 2731 // Sort the live stack so that we can quickly binary search it later. 2732 CHECK(VerifyMissingCardMarks()) << "Pre " << gc->GetName() 2733 << " missing card mark verification failed\n" << DumpSpaces(); 2734 SwapStacks(self); 2735 } 2736 if (verify_mod_union_table_) { 2737 TimingLogger::ScopedTiming t2("(Paused)PreGcVerifyModUnionTables", timings); 2738 ReaderMutexLock reader_lock(self, *Locks::heap_bitmap_lock_); 2739 for (const auto& table_pair : mod_union_tables_) { 2740 accounting::ModUnionTable* mod_union_table = table_pair.second; 2741 mod_union_table->UpdateAndMarkReferences(IdentityMarkHeapReferenceCallback, nullptr); 2742 mod_union_table->Verify(); 2743 } 2744 } 2745} 2746 2747void Heap::PreGcVerification(collector::GarbageCollector* gc) { 2748 if (verify_pre_gc_heap_ || verify_missing_card_marks_ || verify_mod_union_table_) { 2749 collector::GarbageCollector::ScopedPause pause(gc); 2750 PreGcVerificationPaused(gc); 2751 } 2752} 2753 2754void Heap::PrePauseRosAllocVerification(collector::GarbageCollector* gc) { 2755 UNUSED(gc); 2756 // TODO: Add a new runtime option for this? 2757 if (verify_pre_gc_rosalloc_) { 2758 RosAllocVerification(current_gc_iteration_.GetTimings(), "PreGcRosAllocVerification"); 2759 } 2760} 2761 2762void Heap::PreSweepingGcVerification(collector::GarbageCollector* gc) { 2763 Thread* const self = Thread::Current(); 2764 TimingLogger* const timings = current_gc_iteration_.GetTimings(); 2765 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2766 // Called before sweeping occurs since we want to make sure we are not going so reclaim any 2767 // reachable objects. 2768 if (verify_pre_sweeping_heap_) { 2769 TimingLogger::ScopedTiming t2("(Paused)PostSweepingVerifyHeapReferences", timings); 2770 CHECK_NE(self->GetState(), kRunnable); 2771 { 2772 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2773 // Swapping bound bitmaps does nothing. 2774 gc->SwapBitmaps(); 2775 } 2776 // Pass in false since concurrent reference processing can mean that the reference referents 2777 // may point to dead objects at the point which PreSweepingGcVerification is called. 2778 size_t failures = VerifyHeapReferences(false); 2779 if (failures > 0) { 2780 LOG(FATAL) << "Pre sweeping " << gc->GetName() << " GC verification failed with " << failures 2781 << " failures"; 2782 } 2783 { 2784 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 2785 gc->SwapBitmaps(); 2786 } 2787 } 2788 if (verify_pre_sweeping_rosalloc_) { 2789 RosAllocVerification(timings, "PreSweepingRosAllocVerification"); 2790 } 2791} 2792 2793void Heap::PostGcVerificationPaused(collector::GarbageCollector* gc) { 2794 // Only pause if we have to do some verification. 2795 Thread* const self = Thread::Current(); 2796 TimingLogger* const timings = GetCurrentGcIteration()->GetTimings(); 2797 TimingLogger::ScopedTiming t(__FUNCTION__, timings); 2798 if (verify_system_weaks_) { 2799 ReaderMutexLock mu2(self, *Locks::heap_bitmap_lock_); 2800 collector::MarkSweep* mark_sweep = down_cast<collector::MarkSweep*>(gc); 2801 mark_sweep->VerifySystemWeaks(); 2802 } 2803 if (verify_post_gc_rosalloc_) { 2804 RosAllocVerification(timings, "(Paused)PostGcRosAllocVerification"); 2805 } 2806 if (verify_post_gc_heap_) { 2807 TimingLogger::ScopedTiming t2("(Paused)PostGcVerifyHeapReferences", timings); 2808 size_t failures = VerifyHeapReferences(); 2809 if (failures > 0) { 2810 LOG(FATAL) << "Pre " << gc->GetName() << " heap verification failed with " << failures 2811 << " failures"; 2812 } 2813 } 2814} 2815 2816void Heap::PostGcVerification(collector::GarbageCollector* gc) { 2817 if (verify_system_weaks_ || verify_post_gc_rosalloc_ || verify_post_gc_heap_) { 2818 collector::GarbageCollector::ScopedPause pause(gc); 2819 PostGcVerificationPaused(gc); 2820 } 2821} 2822 2823void Heap::RosAllocVerification(TimingLogger* timings, const char* name) { 2824 TimingLogger::ScopedTiming t(name, timings); 2825 for (const auto& space : continuous_spaces_) { 2826 if (space->IsRosAllocSpace()) { 2827 VLOG(heap) << name << " : " << space->GetName(); 2828 space->AsRosAllocSpace()->Verify(); 2829 } 2830 } 2831} 2832 2833collector::GcType Heap::WaitForGcToComplete(GcCause cause, Thread* self) { 2834 ScopedThreadStateChange tsc(self, kWaitingForGcToComplete); 2835 MutexLock mu(self, *gc_complete_lock_); 2836 return WaitForGcToCompleteLocked(cause, self); 2837} 2838 2839collector::GcType Heap::WaitForGcToCompleteLocked(GcCause cause, Thread* self) { 2840 collector::GcType last_gc_type = collector::kGcTypeNone; 2841 uint64_t wait_start = NanoTime(); 2842 while (collector_type_running_ != kCollectorTypeNone) { 2843 ATRACE_BEGIN("GC: Wait For Completion"); 2844 // We must wait, change thread state then sleep on gc_complete_cond_; 2845 gc_complete_cond_->Wait(self); 2846 last_gc_type = last_gc_type_; 2847 ATRACE_END(); 2848 } 2849 uint64_t wait_time = NanoTime() - wait_start; 2850 total_wait_time_ += wait_time; 2851 if (wait_time > long_pause_log_threshold_) { 2852 LOG(INFO) << "WaitForGcToComplete blocked for " << PrettyDuration(wait_time) 2853 << " for cause " << cause; 2854 } 2855 return last_gc_type; 2856} 2857 2858void Heap::DumpForSigQuit(std::ostream& os) { 2859 os << "Heap: " << GetPercentFree() << "% free, " << PrettySize(GetBytesAllocated()) << "/" 2860 << PrettySize(GetTotalMemory()) << "; " << GetObjectsAllocated() << " objects\n"; 2861 DumpGcPerformanceInfo(os); 2862} 2863 2864size_t Heap::GetPercentFree() { 2865 return static_cast<size_t>(100.0f * static_cast<float>(GetFreeMemory()) / max_allowed_footprint_); 2866} 2867 2868void Heap::SetIdealFootprint(size_t max_allowed_footprint) { 2869 if (max_allowed_footprint > GetMaxMemory()) { 2870 VLOG(gc) << "Clamp target GC heap from " << PrettySize(max_allowed_footprint) << " to " 2871 << PrettySize(GetMaxMemory()); 2872 max_allowed_footprint = GetMaxMemory(); 2873 } 2874 max_allowed_footprint_ = max_allowed_footprint; 2875} 2876 2877bool Heap::IsMovableObject(const mirror::Object* obj) const { 2878 if (kMovingCollector) { 2879 space::Space* space = FindContinuousSpaceFromObject(obj, true); 2880 if (space != nullptr) { 2881 // TODO: Check large object? 2882 return space->CanMoveObjects(); 2883 } 2884 } 2885 return false; 2886} 2887 2888void Heap::UpdateMaxNativeFootprint() { 2889 size_t native_size = native_bytes_allocated_.LoadRelaxed(); 2890 // TODO: Tune the native heap utilization to be a value other than the java heap utilization. 2891 size_t target_size = native_size / GetTargetHeapUtilization(); 2892 if (target_size > native_size + max_free_) { 2893 target_size = native_size + max_free_; 2894 } else if (target_size < native_size + min_free_) { 2895 target_size = native_size + min_free_; 2896 } 2897 native_footprint_gc_watermark_ = std::min(growth_limit_, target_size); 2898} 2899 2900collector::GarbageCollector* Heap::FindCollectorByGcType(collector::GcType gc_type) { 2901 for (const auto& collector : garbage_collectors_) { 2902 if (collector->GetCollectorType() == collector_type_ && 2903 collector->GetGcType() == gc_type) { 2904 return collector; 2905 } 2906 } 2907 return nullptr; 2908} 2909 2910double Heap::HeapGrowthMultiplier() const { 2911 // If we don't care about pause times we are background, so return 1.0. 2912 if (!CareAboutPauseTimes() || IsLowMemoryMode()) { 2913 return 1.0; 2914 } 2915 return foreground_heap_growth_multiplier_; 2916} 2917 2918void Heap::GrowForUtilization(collector::GarbageCollector* collector_ran, 2919 uint64_t bytes_allocated_before_gc) { 2920 // We know what our utilization is at this moment. 2921 // This doesn't actually resize any memory. It just lets the heap grow more when necessary. 2922 const uint64_t bytes_allocated = GetBytesAllocated(); 2923 uint64_t target_size; 2924 collector::GcType gc_type = collector_ran->GetGcType(); 2925 const double multiplier = HeapGrowthMultiplier(); // Use the multiplier to grow more for 2926 // foreground. 2927 const uint64_t adjusted_min_free = static_cast<uint64_t>(min_free_ * multiplier); 2928 const uint64_t adjusted_max_free = static_cast<uint64_t>(max_free_ * multiplier); 2929 if (gc_type != collector::kGcTypeSticky) { 2930 // Grow the heap for non sticky GC. 2931 ssize_t delta = bytes_allocated / GetTargetHeapUtilization() - bytes_allocated; 2932 CHECK_GE(delta, 0); 2933 target_size = bytes_allocated + delta * multiplier; 2934 target_size = std::min(target_size, bytes_allocated + adjusted_max_free); 2935 target_size = std::max(target_size, bytes_allocated + adjusted_min_free); 2936 native_need_to_run_finalization_ = true; 2937 next_gc_type_ = collector::kGcTypeSticky; 2938 } else { 2939 collector::GcType non_sticky_gc_type = 2940 HasZygoteSpace() ? collector::kGcTypePartial : collector::kGcTypeFull; 2941 // Find what the next non sticky collector will be. 2942 collector::GarbageCollector* non_sticky_collector = FindCollectorByGcType(non_sticky_gc_type); 2943 // If the throughput of the current sticky GC >= throughput of the non sticky collector, then 2944 // do another sticky collection next. 2945 // We also check that the bytes allocated aren't over the footprint limit in order to prevent a 2946 // pathological case where dead objects which aren't reclaimed by sticky could get accumulated 2947 // if the sticky GC throughput always remained >= the full/partial throughput. 2948 if (current_gc_iteration_.GetEstimatedThroughput() * kStickyGcThroughputAdjustment >= 2949 non_sticky_collector->GetEstimatedMeanThroughput() && 2950 non_sticky_collector->NumberOfIterations() > 0 && 2951 bytes_allocated <= max_allowed_footprint_) { 2952 next_gc_type_ = collector::kGcTypeSticky; 2953 } else { 2954 next_gc_type_ = non_sticky_gc_type; 2955 } 2956 // If we have freed enough memory, shrink the heap back down. 2957 if (bytes_allocated + adjusted_max_free < max_allowed_footprint_) { 2958 target_size = bytes_allocated + adjusted_max_free; 2959 } else { 2960 target_size = std::max(bytes_allocated, static_cast<uint64_t>(max_allowed_footprint_)); 2961 } 2962 } 2963 if (!ignore_max_footprint_) { 2964 SetIdealFootprint(target_size); 2965 if (IsGcConcurrent()) { 2966 const uint64_t freed_bytes = current_gc_iteration_.GetFreedBytes() + 2967 current_gc_iteration_.GetFreedLargeObjectBytes(); 2968 // Bytes allocated will shrink by freed_bytes after the GC runs, so if we want to figure out 2969 // how many bytes were allocated during the GC we need to add freed_bytes back on. 2970 CHECK_GE(bytes_allocated + freed_bytes, bytes_allocated_before_gc); 2971 const uint64_t bytes_allocated_during_gc = bytes_allocated + freed_bytes - 2972 bytes_allocated_before_gc; 2973 // Calculate when to perform the next ConcurrentGC. 2974 // Calculate the estimated GC duration. 2975 const double gc_duration_seconds = NsToMs(current_gc_iteration_.GetDurationNs()) / 1000.0; 2976 // Estimate how many remaining bytes we will have when we need to start the next GC. 2977 size_t remaining_bytes = bytes_allocated_during_gc * gc_duration_seconds; 2978 remaining_bytes = std::min(remaining_bytes, kMaxConcurrentRemainingBytes); 2979 remaining_bytes = std::max(remaining_bytes, kMinConcurrentRemainingBytes); 2980 if (UNLIKELY(remaining_bytes > max_allowed_footprint_)) { 2981 // A never going to happen situation that from the estimated allocation rate we will exceed 2982 // the applications entire footprint with the given estimated allocation rate. Schedule 2983 // another GC nearly straight away. 2984 remaining_bytes = kMinConcurrentRemainingBytes; 2985 } 2986 DCHECK_LE(remaining_bytes, max_allowed_footprint_); 2987 DCHECK_LE(max_allowed_footprint_, GetMaxMemory()); 2988 // Start a concurrent GC when we get close to the estimated remaining bytes. When the 2989 // allocation rate is very high, remaining_bytes could tell us that we should start a GC 2990 // right away. 2991 concurrent_start_bytes_ = std::max(max_allowed_footprint_ - remaining_bytes, 2992 static_cast<size_t>(bytes_allocated)); 2993 } 2994 } 2995} 2996 2997void Heap::ClampGrowthLimit() { 2998 capacity_ = growth_limit_; 2999 for (const auto& space : continuous_spaces_) { 3000 if (space->IsMallocSpace()) { 3001 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3002 malloc_space->ClampGrowthLimit(); 3003 } 3004 } 3005 // This space isn't added for performance reasons. 3006 if (main_space_backup_.get() != nullptr) { 3007 main_space_backup_->ClampGrowthLimit(); 3008 } 3009} 3010 3011void Heap::ClearGrowthLimit() { 3012 growth_limit_ = capacity_; 3013 for (const auto& space : continuous_spaces_) { 3014 if (space->IsMallocSpace()) { 3015 gc::space::MallocSpace* malloc_space = space->AsMallocSpace(); 3016 malloc_space->ClearGrowthLimit(); 3017 malloc_space->SetFootprintLimit(malloc_space->Capacity()); 3018 } 3019 } 3020 // This space isn't added for performance reasons. 3021 if (main_space_backup_.get() != nullptr) { 3022 main_space_backup_->ClearGrowthLimit(); 3023 main_space_backup_->SetFootprintLimit(main_space_backup_->Capacity()); 3024 } 3025} 3026 3027void Heap::AddFinalizerReference(Thread* self, mirror::Object** object) { 3028 ScopedObjectAccess soa(self); 3029 ScopedLocalRef<jobject> arg(self->GetJniEnv(), soa.AddLocalReference<jobject>(*object)); 3030 jvalue args[1]; 3031 args[0].l = arg.get(); 3032 InvokeWithJValues(soa, nullptr, WellKnownClasses::java_lang_ref_FinalizerReference_add, args); 3033 // Restore object in case it gets moved. 3034 *object = soa.Decode<mirror::Object*>(arg.get()); 3035} 3036 3037void Heap::RequestConcurrentGCAndSaveObject(Thread* self, mirror::Object** obj) { 3038 StackHandleScope<1> hs(self); 3039 HandleWrapper<mirror::Object> wrapper(hs.NewHandleWrapper(obj)); 3040 RequestConcurrentGC(self); 3041} 3042 3043class Heap::ConcurrentGCTask : public HeapTask { 3044 public: 3045 explicit ConcurrentGCTask(uint64_t target_time) : HeapTask(target_time) { } 3046 virtual void Run(Thread* self) OVERRIDE { 3047 gc::Heap* heap = Runtime::Current()->GetHeap(); 3048 heap->ConcurrentGC(self); 3049 heap->ClearConcurrentGCRequest(); 3050 } 3051}; 3052 3053static bool CanAddHeapTask(Thread* self) LOCKS_EXCLUDED(Locks::runtime_shutdown_lock_) { 3054 Runtime* runtime = Runtime::Current(); 3055 return runtime != nullptr && runtime->IsFinishedStarting() && !runtime->IsShuttingDown(self) && 3056 !self->IsHandlingStackOverflow(); 3057} 3058 3059void Heap::ClearConcurrentGCRequest() { 3060 concurrent_gc_pending_.StoreRelaxed(false); 3061} 3062 3063void Heap::RequestConcurrentGC(Thread* self) { 3064 if (CanAddHeapTask(self) && 3065 concurrent_gc_pending_.CompareExchangeStrongSequentiallyConsistent(false, true)) { 3066 task_processor_->AddTask(self, new ConcurrentGCTask(NanoTime())); // Start straight away. 3067 } 3068} 3069 3070void Heap::ConcurrentGC(Thread* self) { 3071 if (!Runtime::Current()->IsShuttingDown(self)) { 3072 // Wait for any GCs currently running to finish. 3073 if (WaitForGcToComplete(kGcCauseBackground, self) == collector::kGcTypeNone) { 3074 // If the we can't run the GC type we wanted to run, find the next appropriate one and try that 3075 // instead. E.g. can't do partial, so do full instead. 3076 if (CollectGarbageInternal(next_gc_type_, kGcCauseBackground, false) == 3077 collector::kGcTypeNone) { 3078 for (collector::GcType gc_type : gc_plan_) { 3079 // Attempt to run the collector, if we succeed, we are done. 3080 if (gc_type > next_gc_type_ && 3081 CollectGarbageInternal(gc_type, kGcCauseBackground, false) != 3082 collector::kGcTypeNone) { 3083 break; 3084 } 3085 } 3086 } 3087 } 3088 } 3089} 3090 3091class Heap::CollectorTransitionTask : public HeapTask { 3092 public: 3093 explicit CollectorTransitionTask(uint64_t target_time) : HeapTask(target_time) { } 3094 virtual void Run(Thread* self) OVERRIDE { 3095 gc::Heap* heap = Runtime::Current()->GetHeap(); 3096 heap->DoPendingCollectorTransition(); 3097 heap->ClearPendingCollectorTransition(self); 3098 } 3099}; 3100 3101void Heap::ClearPendingCollectorTransition(Thread* self) { 3102 MutexLock mu(self, *pending_task_lock_); 3103 pending_collector_transition_ = nullptr; 3104} 3105 3106void Heap::RequestCollectorTransition(CollectorType desired_collector_type, uint64_t delta_time) { 3107 Thread* self = Thread::Current(); 3108 desired_collector_type_ = desired_collector_type; 3109 if (desired_collector_type_ == collector_type_ || !CanAddHeapTask(self)) { 3110 return; 3111 } 3112 CollectorTransitionTask* added_task = nullptr; 3113 const uint64_t target_time = NanoTime() + delta_time; 3114 { 3115 MutexLock mu(self, *pending_task_lock_); 3116 // If we have an existing collector transition, update the targe time to be the new target. 3117 if (pending_collector_transition_ != nullptr) { 3118 task_processor_->UpdateTargetRunTime(self, pending_collector_transition_, target_time); 3119 return; 3120 } 3121 added_task = new CollectorTransitionTask(target_time); 3122 pending_collector_transition_ = added_task; 3123 } 3124 task_processor_->AddTask(self, added_task); 3125} 3126 3127class Heap::HeapTrimTask : public HeapTask { 3128 public: 3129 explicit HeapTrimTask(uint64_t delta_time) : HeapTask(NanoTime() + delta_time) { } 3130 virtual void Run(Thread* self) OVERRIDE { 3131 gc::Heap* heap = Runtime::Current()->GetHeap(); 3132 heap->Trim(self); 3133 heap->ClearPendingTrim(self); 3134 } 3135}; 3136 3137void Heap::ClearPendingTrim(Thread* self) { 3138 MutexLock mu(self, *pending_task_lock_); 3139 pending_heap_trim_ = nullptr; 3140} 3141 3142void Heap::RequestTrim(Thread* self) { 3143 if (!CanAddHeapTask(self)) { 3144 return; 3145 } 3146 // GC completed and now we must decide whether to request a heap trim (advising pages back to the 3147 // kernel) or not. Issuing a request will also cause trimming of the libc heap. As a trim scans 3148 // a space it will hold its lock and can become a cause of jank. 3149 // Note, the large object space self trims and the Zygote space was trimmed and unchanging since 3150 // forking. 3151 3152 // We don't have a good measure of how worthwhile a trim might be. We can't use the live bitmap 3153 // because that only marks object heads, so a large array looks like lots of empty space. We 3154 // don't just call dlmalloc all the time, because the cost of an _attempted_ trim is proportional 3155 // to utilization (which is probably inversely proportional to how much benefit we can expect). 3156 // We could try mincore(2) but that's only a measure of how many pages we haven't given away, 3157 // not how much use we're making of those pages. 3158 HeapTrimTask* added_task = nullptr; 3159 { 3160 MutexLock mu(self, *pending_task_lock_); 3161 if (pending_heap_trim_ != nullptr) { 3162 // Already have a heap trim request in task processor, ignore this request. 3163 return; 3164 } 3165 added_task = new HeapTrimTask(kHeapTrimWait); 3166 pending_heap_trim_ = added_task; 3167 } 3168 task_processor_->AddTask(self, added_task); 3169} 3170 3171void Heap::RevokeThreadLocalBuffers(Thread* thread) { 3172 if (rosalloc_space_ != nullptr) { 3173 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3174 } 3175 if (bump_pointer_space_ != nullptr) { 3176 bump_pointer_space_->RevokeThreadLocalBuffers(thread); 3177 } 3178} 3179 3180void Heap::RevokeRosAllocThreadLocalBuffers(Thread* thread) { 3181 if (rosalloc_space_ != nullptr) { 3182 rosalloc_space_->RevokeThreadLocalBuffers(thread); 3183 } 3184} 3185 3186void Heap::RevokeAllThreadLocalBuffers() { 3187 if (rosalloc_space_ != nullptr) { 3188 rosalloc_space_->RevokeAllThreadLocalBuffers(); 3189 } 3190 if (bump_pointer_space_ != nullptr) { 3191 bump_pointer_space_->RevokeAllThreadLocalBuffers(); 3192 } 3193} 3194 3195bool Heap::IsGCRequestPending() const { 3196 return concurrent_gc_pending_.LoadRelaxed(); 3197} 3198 3199void Heap::RunFinalization(JNIEnv* env) { 3200 // Can't do this in WellKnownClasses::Init since System is not properly set up at that point. 3201 if (WellKnownClasses::java_lang_System_runFinalization == nullptr) { 3202 CHECK(WellKnownClasses::java_lang_System != nullptr); 3203 WellKnownClasses::java_lang_System_runFinalization = 3204 CacheMethod(env, WellKnownClasses::java_lang_System, true, "runFinalization", "()V"); 3205 CHECK(WellKnownClasses::java_lang_System_runFinalization != nullptr); 3206 } 3207 env->CallStaticVoidMethod(WellKnownClasses::java_lang_System, 3208 WellKnownClasses::java_lang_System_runFinalization); 3209} 3210 3211void Heap::RegisterNativeAllocation(JNIEnv* env, size_t bytes) { 3212 Thread* self = ThreadForEnv(env); 3213 if (native_need_to_run_finalization_) { 3214 RunFinalization(env); 3215 UpdateMaxNativeFootprint(); 3216 native_need_to_run_finalization_ = false; 3217 } 3218 // Total number of native bytes allocated. 3219 size_t new_native_bytes_allocated = native_bytes_allocated_.FetchAndAddSequentiallyConsistent(bytes); 3220 new_native_bytes_allocated += bytes; 3221 if (new_native_bytes_allocated > native_footprint_gc_watermark_) { 3222 collector::GcType gc_type = HasZygoteSpace() ? collector::kGcTypePartial : 3223 collector::kGcTypeFull; 3224 3225 // The second watermark is higher than the gc watermark. If you hit this it means you are 3226 // allocating native objects faster than the GC can keep up with. 3227 if (new_native_bytes_allocated > growth_limit_) { 3228 if (WaitForGcToComplete(kGcCauseForNativeAlloc, self) != collector::kGcTypeNone) { 3229 // Just finished a GC, attempt to run finalizers. 3230 RunFinalization(env); 3231 CHECK(!env->ExceptionCheck()); 3232 } 3233 // If we still are over the watermark, attempt a GC for alloc and run finalizers. 3234 if (new_native_bytes_allocated > growth_limit_) { 3235 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3236 RunFinalization(env); 3237 native_need_to_run_finalization_ = false; 3238 CHECK(!env->ExceptionCheck()); 3239 } 3240 // We have just run finalizers, update the native watermark since it is very likely that 3241 // finalizers released native managed allocations. 3242 UpdateMaxNativeFootprint(); 3243 } else if (!IsGCRequestPending()) { 3244 if (IsGcConcurrent()) { 3245 RequestConcurrentGC(self); 3246 } else { 3247 CollectGarbageInternal(gc_type, kGcCauseForNativeAlloc, false); 3248 } 3249 } 3250 } 3251} 3252 3253void Heap::RegisterNativeFree(JNIEnv* env, size_t bytes) { 3254 size_t expected_size; 3255 do { 3256 expected_size = native_bytes_allocated_.LoadRelaxed(); 3257 if (UNLIKELY(bytes > expected_size)) { 3258 ScopedObjectAccess soa(env); 3259 env->ThrowNew(WellKnownClasses::java_lang_RuntimeException, 3260 StringPrintf("Attempted to free %zd native bytes with only %zd native bytes " 3261 "registered as allocated", bytes, expected_size).c_str()); 3262 break; 3263 } 3264 } while (!native_bytes_allocated_.CompareExchangeWeakRelaxed(expected_size, 3265 expected_size - bytes)); 3266} 3267 3268size_t Heap::GetTotalMemory() const { 3269 return std::max(max_allowed_footprint_, GetBytesAllocated()); 3270} 3271 3272void Heap::AddModUnionTable(accounting::ModUnionTable* mod_union_table) { 3273 DCHECK(mod_union_table != nullptr); 3274 mod_union_tables_.Put(mod_union_table->GetSpace(), mod_union_table); 3275} 3276 3277void Heap::CheckPreconditionsForAllocObject(mirror::Class* c, size_t byte_count) { 3278 CHECK(c == nullptr || (c->IsClassClass() && byte_count >= sizeof(mirror::Class)) || 3279 (c->IsVariableSize() || c->GetObjectSize() == byte_count)); 3280 CHECK_GE(byte_count, sizeof(mirror::Object)); 3281} 3282 3283void Heap::AddRememberedSet(accounting::RememberedSet* remembered_set) { 3284 CHECK(remembered_set != nullptr); 3285 space::Space* space = remembered_set->GetSpace(); 3286 CHECK(space != nullptr); 3287 CHECK(remembered_sets_.find(space) == remembered_sets_.end()) << space; 3288 remembered_sets_.Put(space, remembered_set); 3289 CHECK(remembered_sets_.find(space) != remembered_sets_.end()) << space; 3290} 3291 3292void Heap::RemoveRememberedSet(space::Space* space) { 3293 CHECK(space != nullptr); 3294 auto it = remembered_sets_.find(space); 3295 CHECK(it != remembered_sets_.end()); 3296 delete it->second; 3297 remembered_sets_.erase(it); 3298 CHECK(remembered_sets_.find(space) == remembered_sets_.end()); 3299} 3300 3301void Heap::ClearMarkedObjects() { 3302 // Clear all of the spaces' mark bitmaps. 3303 for (const auto& space : GetContinuousSpaces()) { 3304 accounting::ContinuousSpaceBitmap* mark_bitmap = space->GetMarkBitmap(); 3305 if (space->GetLiveBitmap() != mark_bitmap) { 3306 mark_bitmap->Clear(); 3307 } 3308 } 3309 // Clear the marked objects in the discontinous space object sets. 3310 for (const auto& space : GetDiscontinuousSpaces()) { 3311 space->GetMarkBitmap()->Clear(); 3312 } 3313} 3314 3315} // namespace gc 3316} // namespace art 3317